BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the formation of a novel, stable
C-10 carba trioxane dimer that may easily be transformed into
different trioxane dimers. Some of these dimers are 10 times more
antimalarially potent in vitro than artemisinin. These anticancer
dimers selectively inhibit growth in vitro of several human cancer
cell lines without being cytotoxic. The present invention relates
also to water-soluble carboxylic acid derivatives that are
thermally stable, that are more orally efficacious antimalarials
than either artelinic acid or clinically used sodium artesunate,
and that have potent and selective anticancer activities. The
present invention further relates to antimalarial trioxane dimers
that are safer and more efficacious than sodium artesunate.
2. Description of the State of
Art
Each year approximately 200-300 million people experience a
malarial illness and over 1 million individuals die. In patients
with severe and complicated disease, the mortality rate is between
20 and 50%.
Plasmodium is the genus of protozoan parasites which is
responsible for all cases of human malaria and Plasmodium
falciparum is the species of parasite that is responsible for the
vast majority of fatal malaria infections. Malaria has
traditionally been treated with quinolines such as chloroquine,
quinine, mefloquine, and primaquine and with antifolates such as
sulfadoxine-pyrimethamine. Unfortunately, most P. falciparum
strains have now become resistant to chloroquine, and some, such
as those in Southeast Asia, have also developed resistance to
mefloquine and halofantrine; multidrug resistance is developing in
Africa also.
The endoperoxides are a promising class of antimalarial drugs
which may meet the dual challenges posed by drug-resistant
parasites and the rapid progression of malarial illness. The first
generation endoperoxides include natural artemisinin and several
synthetic derivatives, discussed in further detail below.
Artemisia annua L., also known as qinghao or sweet wormwood, is a
pervasive weed that has been used for many centuries in Chinese
traditional medicine as a treatment for fever and malaria. Its
earliest mention, for use in hemorrhoids, occurs in the Recipes
for 52 Kinds of Diseases found in the Mawangdui Han dynasty tomb
dating from 168 B.C. Nearly five hundred years later Ge Hong wrote
the Zhou Hou Bei Ji Fang (Handbook of Prescriptions for Emergency
Treatments) in which he advised that a water extract of qinghao
was effective at reducing fevers. In 1596, Li Shizhen, the famous
herbalist, wrote that chills and fever of malaria can be combated
by qinghao preparations. Finally, in 1972, Chinese chemists
isolated from the leafy portions of the plant the substance
responsible for its reputed medicinal action. This crystalline
compound, called qinghaosu, also referred to as QHS or
artemisinin, is a sesquiterpene lactone with an internal peroxide
linkage.
Artemisinin is a member of the amorphane subgroup of cadinenes and
has the following structure (I); "Art" will be used for shorthand
in many of the figures.
##STR00001## Artemisinin or QHS was the subject of a 1979 study
conducted by the Qinghaosu Antimalarial Coordinating Research
Group involving the treatment of 2099 cases of malaria (P. vivax
and P. falciparum in a ratio of about 3:1 ) with different dosage
forms of QHS, leading to the clinical cure of all patients. See,
Qinghaosu Antimalarial Coordinating Research Group, Chin. Med. J.,
92:811 (1979). Since that time artemisinin has been used
successfully in many thousand malaria patients throughout the
world including those infected with both chloroquine-sensitive and
chloroquine-resistant strains of P. falciparum. Assay of
artemisinin against P. falciparum in vitro revealed that its
potency is comparable to that of chloroquine in two Hanian strains
(Z. Ye, et al., J. Trad. Chin. Med., 3:95 (1983)) and of
mefloquine in the Camp (chloroquine-susceptible) and Smith
(chloroquine-resistant) strains, D. L. Klayman, et al., J. Nat.
Prod., 47:715 (1984).
Although artemisinin is effective at suppressing the parasitemias
of P. vivax and P. falciparum, the problems encountered with
recrudescence, and the compound's insolubility in water, led
scientists to modify artemisinin chemically, a difficult task
because of the chemical reactivity of the peroxide linkage which
is believed to be an essential moiety for antimalarial activity.
Reduction of artemisinin in the presence of sodium borohydride
results in the production of dihydroartemisinin (II-1) or DHQHS,
(illustrated in structure II below), in which the lactone group is
converted to a lactol (hemiacetal) function, with properties
similar to artemisinin. Artemisinin in methanol is reduced with
sodium borohydride to an equilibrium mixture of .alpha.- and
.beta.-isomers of dihydroartemisinin. Using dihydroartemisinin as
a starting compound a large number of other derivatives, such as,
##STR00002## artemether (compound II-2), arteether (II-3), sodium
artesunate (II-4), artelinic acid (II-5), sodium artelinate
(II-6), dihydroartemisinin condensation by-product (II-7) and the
olefinic compound, structure III,
##STR00003## have been produced.
Artemether (II-2) is produced by reacting
.beta.-dihydroartemisinin with boron trifluoride (BF.sub.3)
etherate or HCl in methanol:benzene (1:2) at room temperature. A
mixture of .beta.-and .alpha.-artemether (70:30) is obtained, from
which the former is isolated by column chromatography and
recrystallized from hexane or methanol, R. Haynes, Transactions of
the Royal Society of Tropical Medicine and Hygiene, 88(l):
S1/23-S1/26 (1994). For arteether (II-3), (Brossi, et al., 1988),
the .alpha.-isomer is equilibrated (epimerized) to the
.beta.-isomer in ethanol:benzene mixture containing BF.sub.3
etherate. Treatment of dihydroartemisinin with an unspecified
dehydrating agent yields both the olefinic compound, (III), and
the dihydroartemisinin condensation by-product (II-7), formed on
addition of dihydroartemisinin to (III), M. Cao, et al., Chem.
Abstr., 100:34720k (1984). Until recently, the secondary hydroxy
group in dihydroartemisinin (II-1) provided the only site in an
active artemisinin-related compound that had been used for
derivatization. See B. Venugopalan, "Synthesis of a Novel Ring
Contracted Artemisinin Derivative," Bioorganic & Medicinal
Chemistry Letters, 4(5):751 -752 (1994).
The potency of various artemisinin-derivatives in comparison to
artemisinin as a function of the concentration at which the
parasitemia is 90 percent suppressed (SD.sub.90) was reported by
D. L. Klayman, "Qinghaosu (Artemisinin): An Antimalarial Drug from
China," Science 228:1049-1055 (1985). Dr. Klayman reported that
the olefinic compound III is inactive against P. berghei-infected
mice, whereas the dihydroartemisinin condensation by-product
(II-7) has an SD.sub.90 of 10 mg/Kg in P. berghei-infected mice.
Thus, the dihydroartemisinin ether dimer proved to be less potent
than artemisinin, which has an SD.sub.90of 6.20 mg/Kg. Following,
in order of their overall antimalarial efficacy, are the three
types of derivatives of dihydroartemisinin (II-1) that have been
produced: (artemisinin)<ethers (II, R.dbd.alkyl)<esters [II,
R.dbd.C(.dbd.O)-alkyl or -aryl]<carbonates [II, R.dbd.C
(.dbd.O)O-alkyl or -aryl].
Other rational design of structurally simpler analogs of
artemisinin has led to the synthesis of various trioxanes, some of
which possess excellent antimalarial activity. Posner, G. H., et
al., reported the chemistry and biology of a series of new
structurally simple, easily prepared, racemic 1,2,4-trioxanes
(disclosed in U.S. Pat. No. 5,225,437 and incorporated herein by
reference) that are tricyclic (lacking the lactone ring present in
tetracyclic artemisinin I) and that are derivatives of trioxane
alcohol IV
##STR00004## having the relative stereochemistry shown above.
Especially attractive features of trioxane alcohol IV are the
following: (1) its straightforward and easy preparation from cheap
and readily available starting materials, (2) its availability on
gram scale, and (3) its easy one-step conversion, using standard
chemical transformations, into alcohol derivatives such as esters
and ethers, without destruction of the crucial trioxane framework.
See, Posner, G. H., et al., J Med. Chem., 35:2459-2467 (1992),
incorporated herein by reference. The complete chemical synthesis
of artemisinin and a variety of other derivatives is reviewed by
Sharma, R. P., et al., Heterocycles, 32(8):1593-1638 (1991), and
is incorporated herein by reference.
Metabolic studies by Baker, et al., demonstrated that
.beta.-arteether (II-3), one of the antimalarial derivatives
discussed previously, was rapidly converted by rat liver
microsomes into dihydroartemisinin (II-1). See Baker, J. K., et
al., Biol. Mass. Spect., 20:609-628 (1991). This finding and the
fact that the most effective artemisinin derivatives against
malaria have been ethers or esters of (II-1) suggest that they
were prodrugs for (II-1). The controlled slow formation of (II-1),
however, is not desirable in view of its short half-life in plasma
(less than two hours) and relatively high toxicity.
Unfortunately C-10 acetal derivatives are often unstable (i.e.
easily hydrolyzed) in water. Therefore making hydrolytically
stable C-10 non-acetal carba-derivatives has become a high
priority internationally.
Over the past thirty years only a few drugs isolated from higher
plants have yielded clinical agents, the outstanding examples
being vinblastine and vincristine from the Madagascan periwinkle,
Catharanthus roseus, etoposide, the semi-synthetic lignan, from
Mayapple Podophyllum peltatum and the diterpenoid taxol, commonly
referred to as paclitaxel, from the Pacific yew, Taxus brevifolia.
Of these agents, paclitaxel is the most exciting, recently
receiving approval by the Food and Drug Administration for the
treatment of refractory ovarian cancer. Since the isolation of
artemisinin, there has been a concerted effort by investigators to
study other therapeutic applications of artemisinin and its
derivatives.
National Institutes of Health reported that artemisinin is
inactive against P388 leukemia. See NCI Report on NSC 369397
(tested on 25 Oct. 1983). Later anticancer studies that have been
conducted on cell line panels consisting of 60 lines organized
into nine, disease-related subpanels including leukemia,
non-small-cell lung cancer, colon, CNS, melanoma, ovarian, renal,
prostate and breast cancers, further confirm that artemisinin
displays very little anticancer activity. A series of
artemisinin-related endoperoxides were tested for cytotoxicity to
Ehrlich ascites tumor (EAT) cells using the microculture
tetrazolum (MTT) assay, H. J. Woerdenbag, et al., "Cytotoxicity of
Artemisinin-Related Endoperoxides to Ehrlich Ascites Tumor Cells,"
Journal of Natural Products, 56(6):849-856 (1993). The MTT assay,
used to test the artemisinin-related endoperoxides for
cytotoxicity, is based on the metabolic reduction of soluble
tetrazolium salts into insoluble colored formazan products by
mitochondrial dehydrogenase activity of the tumor cells. As
parameters for cytotoxicity, the IC.sub.50 and IC.sub.80 values,
the drug concentrations causing respectively 50% and 80% growth
inhibition of the tumor cells, were used. Artemisinin (I) had an
IC.sub.50 value of 29.8 .mu.M. Derivatives of dihydroartemisinin
(II-1) being developed as antimalarial drugs (artemether (II-2),
arteether (III-3), sodium artesunate (II-4), artelinic acid (II-5)
and sodium artelinate (II-6)), exhibited a somewhat more potent
cytotoxicity. Their IC.sub.50 values ranged from 12.2 .mu.M to
19.9 .mu.M. The dihydroartemisinin condensation by-product dimer
(II-7), disclosed previously by M. Cao, et a., 1984, was the most
potent cytotoxic agent, its IC.sub.50 being 1.4 .mu.M. At this
drug concentration the condensation by-product (II-7) is
approximately twenty-two times more cytotoxic than artemisinin and
sixty times more cytotoxic than dihydroartemisinin (II-1), the
parent compound.
While artemisinin and its related derivatives (II 1-6) discussed
above demonstrated zero to slight antiproliferative and antitumor
activity, it has been discovered that a class of artemisinin dimer
compounds exhibits antiproliferative and antitumor activities that
are, in vitro, equivalent to or greater than known
antiproliferative and antitumor agents. See, U.S. Pat. No.
5,677,468 incorporated herein by reference. Unfortunately, while
the in vitro results of these artemisinin compounds are
encouraging these compounds do not appear to have significant
antitumor activity on the treatment of tumor cells in mice.
There is still a need, therefore, to develop methods for the
formation of hydrolytically stable C-10 non-acetal
carba-derivatives and structural analogs thereof having
antimalarial, and antiproliferative and antitumor activities that
are equivalent to or greater than those of known antimalarial, and
antiproliferative and antitumor agents, respectively.
SUMMARY OF THE INVENTION
Accordingly, this invention provides a class of artemisinin
related dimers which demonstrate antimalarial and antitumor
activities.
More specifically, this invention provides a class of trioxane
dimers which demonstrate antimalarial and antitumor activities and
that are considerably more stable toward hydrolysis than
artemether and related C-10 ethers and esters.
This invention further provides artemisinin dimers to be used
clinically as chemotherapeutic antimalarial and anticancer drugs.
This invention further provides artemisinin C-10-acetal
derivatives for comparisson to the corresponding dimers, and to be
used clinically as chemotherapeutic antimalarial drugs.
This invention further provides a C-10-carba trioxane dimer that
is easily transformed in one additional step into different
dimers.
This invention further provides water-soluble carboxylic acid
dimers that are thermally stable, that are more orally efficacious
antimalarials than either artelinic acid or clinically used sodium
artesunate, and that have potent and selective anticancer
activities.
Additional objects, advantages and novel features of this
invention shall be set forth in part in the description and
examples that follow, and in part will become apparent to those
skilled in the art upon examination of the following specification
or may be learned by the practice of the invention. The objects
and advantages of the invention may be realized and attained by
means of the instrumentalities, combinations, compositions, and
methods particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a
part of the specification, illustrate the preferred embodiments of
the present invention, and together with the description serve to
explain the principles of the invention.
In the drawings, FIGS. 7-15, the horizontal axis depicts various
dilutions of the test compound, ranging from 10.sup.-4 to
10.sup.-9 molar, that were exposed to the specified cancer cell
lines. The vertical axis (percentage growth) depicts the growth of
the specified cancer cell line when exposed to a specific
concentration of the tested compound as compared to the growth of
the same cancer cell line not exposed to any compound.
In the Drawings:
FIG. 1 schematically
depicts the method of converting artemisinin I into C-10 acetate 2
of the present invention.
FIG. 2 schematically
depicts the method of converting C-10 acetate 2 into C-10
non-acetal trioxane dimer 3 of the present invention.
FIG. 3 schematically
depicts the method of converting C-10 non-acetal trioxane dimer 3
of the present invention into bis-trioxane primary alcohol 4 of
the present invention.
FIG. 4 schematically
depicts the method of converting C-10 non-acetal trioxane dimer 3
of the present invention into bis-trioxane vicinal diol 5 of the
present invention.
FIG. 5 schematically
depicts the method of converting C-10 non-acetal trioxane dimer 3
of the present invention into bis-trioxane epoxide 6 of the
present invention.
FIG. 6 schematically
depicts the method of converting C-10 non-acetal trioxane dimer 3
of the present invention into bis-trioxane ketone 7 of the present
invention.
FIG. 7a depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of paclitaxel.
FIG. 7b depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of artemisinin.
FIG. 7c depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 7d depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 7e depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 7f depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 7g depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 7h depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 7i depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 7j depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 7k depicts the dose
response curves generated by exposing various leukemia cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 8a depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of paclitaxel.
FIG. 8b depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the artemisinin.
FIG. 8c depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
primary alcohol 4 of the present invention.
FIG. 8d depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
vicinal diol 5 of the present invention.
FIG. 8e depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
primary succinate monoester 8a of the present invention.
FIG. 8f depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the succinate ester
9 of the present invention.
FIG. 8g depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 8h depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
tertiary alcohol benzoic acid 11b of the present invention.
FIG. 8i depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
O-acetic acid 12b of the present invention.
FIG. 8j depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
primary alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 8k depicts the dose
response curves generated by exposing various non-small cell lung
cancer cell lines to various concentrations of the bis-trioxane
diphenyl phosphate dimer 14 of the present invention.
FIG. 9a depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of paclitaxel.
FIG. 9b depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of artemisinin.
FIG. 9c depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 9d depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 9e depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 9f depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 9g depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 9h depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 9i depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 9j depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 9k depicts the dose
response curves generated by exposing various colon cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 10a depicts the dose
response curves generated by exposing various CNS cancer cell
lines to various concentrations of paclitaxel.
FIG. 10b depicts the dose
response curves generated by exposing various CNS cancer cell
lines to various concentrations of artemisinin.
FIG. 10c depicts the dose
response curves generated by exposing various CNS cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 10d depicts the dose
response curves generated by exposing various CNS cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 10e depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 10f depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the succinate ester 9 of
the present invention.
FIG. 10g depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 10h depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 10i depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane O-acetic
acid 12b of the present invention.
FIG. 10j depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 10k depicts the dose
response curves generated by exposing various CNS cancer cancer
cell lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 11a depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of paclitaxel.
FIG. 11b depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of artemisinin.
FIG. 11c depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 11d depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 11e depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 11f depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 11g depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 11h depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 11i depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 11j depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 11k depicts the dose
response curves generated by exposing various melanoma cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 12a depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of paclitaxel.
FIG. 12b depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of artemisinin.
FIG. 12c depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 12d depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 12e depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 12f depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 12g depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 12h depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 12i depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 12j depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 12k depicts the dose
response curves generated by exposing various ovarian cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 13a depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of paclitaxel.
FIG. 13b depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of artemisinin.
FIG. 13c depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 13d depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 13e depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 13f depicts the dose
response curves generated by exposing various I renal cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 13g depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 13h depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 13i depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 13j depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 13k depicts the dose
response curves generated by exposing various renal cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 14a depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of paclitaxel.
FIG. 14b depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 14c depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 14d depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 14e depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 14f depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 14g depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 14h depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 14i depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 14j depicts the dose
response curves generated by exposing various prostate cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 15a depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of paclitaxel.
FIG. 15b depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol 4 of the present invention.
FIG. 15c depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane vicinal diol 5
of the present invention.
FIG. 15d depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane primary
succinate monoester 8a of the present invention.
FIG. 15e depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the succinate ester 9 of the
present invention.
FIG. 15f depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c of the present invention.
FIG. 15g depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 15h depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane O-acetic acid
12b of the present invention.
FIG. 15i depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane primary
alcohol isonicotinate N-oxide 13 of the present invention.
FIG. 15j depicts the dose
response curves generated by exposing various breast cancer cell
lines to various concentrations of the bis-trioxane diphenyl
phosphate dimer 14 of the present invention.
FIG. 16 schematically
depicts the method of converting bis-trioxane primary alcohol 4
into bis-trioxane primary succinate monoester 8a of the present
invention.
FIG. 17 schematically
depicts the method of converting bis-trioxane vicinal diol 5 into
the tertiary alcohol primary succinate ester 9 of the present
invention.
FIG. 18 schematically
depicts the method of converting bis-trioxane epoxide 6 into
bis-trioxane .beta.-hydroxysulfide ester 10a, sulfide to sulfone
oxidation gave bis-trioxane .beta.-hydroxysulfone ester 10b that
was saponified into bis-trioxane .beta.-hydroxysulfone benzoic
acid 10c of the present invention.
FIG. 19 schematically
depicts the method of converting bis-trioxane ketone 7 into
bis-trioxane styryl tertiary alcohol 11a and bis-trioxane tertiary
alcohol benzoic acid 11b of the present invention.
FIG. 20 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane O-allyl ether 12a and bis-trioxane O-acetic acid 12b
of the present invention.
FIG. 21 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane primary alcohol isonicotinate 8b of the present
invention.
FIG. 22 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane primary alcohol isonicotinate N-oxide 13 of the
present invention.
FIG. 23 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane primary alcohol nicotinate N-oxide 15 of the present
invention.
FIG. 24 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane phosphonic acid monoester 16 of the present
invention.
FIG. 25 schematically
depicts the method of converting primary alcohol 4 to the
bis-trioxane diphenyl phosphate 14 of the present invention.
FIG. 26 schematically
depicts the method of converting bis-trioxane ketone 7 to the
bis-trioxane secondary alcohol 17 of the present invention.
FIG. 27 schematically
depicts the method of converting bis-trioxane vicinal diol 5 to
the bis-trioxane vicinal diol isonicotinate N-oxide 18 of the
present invention.
FIG. 28 schematically
depicts the method of converting bis-trioxane vicinal diol 5 to
the bis-trioxane isobutyric acid 19 of the present invention.
FIG. 29 schematically
depicts the method of converting bis-trioxane vicinal diol 5 to
the bis-trioxane .beta.-hydroxy O-allyl ether 20 and then on to
the bis-trioxane .beta.-hydroxy O-acetic acid 21 of the present
invention.
FIG. 30 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol picolinate 22 of the present
invention.
FIG. 31 schematically
depicts the method of converting bis-trioxane vicinal diol 5 to
the bis-trioxane vicinal diol nicotinate N-oxide 23 of the present
invention.
FIG. 32 schematically
depicts the method of converting bis-trioxane secondary alcohol 17
to the bis-trioxane secondary alcohol isonicotinate N-oxide 24 of
the present invention.
FIG. 33 schematically
depicts the method of converting bis-trioxane secondary alcohol 17
to the bis-trioxane secondary alcohol nicotinate N-oxide 25 of the
present invention.
FIG. 34 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol diethyl phosphoric acid triester
26 of the present invention.
FIG. 35 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol dimethyl phosphoric acid triester
27 of the present invention.
FIG. 36 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol p-trifluoromethylbenzoate 28 of
the present invention.
FIG. 37 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol 3,5-ditrifluoromethylbenzoate 29
of the present invention.
FIG. 38 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol dimethylgylcinate 30 of the
present invention.
FIG. 39 schematically
depicts the method of converting artemisinin 1 to the
dihydroartemisinin 31 of the present invention.
FIG. 40 schematically
depicts the method of converting dihydroartemisinin 31 to the
.alpha.-dihydroartemisinin dimethylglycinate 32 of the present
invention.
FIG. 41 schematically
depicts the method of converting dihydroartemisinin 31 to the
.alpha.-dihydroartemisinin isonicotinate N-oxide 33 of the present
invention.
FIG. 42 schematically
depicts the method of converting bis-trioxane ketone 7 to the
bis-trioxane allyl tertiary alcohol 34 and the method of
converting bis-trioxane allyl tertiary alcohol 34 to the
bis-trioxane tertiary alcohol carboxylic acid 35 of the present
invention.
FIG. 43 schematically
depicts the method of converting bis-trioxane primary alcohol 4 to
the bis-trioxane primary alcohol methyl carbonate 36 and the
method of converting bis-trioxane primary alcohol 4 to the
bis-trioxane primary alcohol ethyl carbonate 37 of the present
invention.
FIG. 44 schematically
depicts the method of converting bis-trioxane ketone 7 to the
bis-trioxane tertiary alcohol methyl sulfonate 38, the method of
converting bis-trioxane ketone 7 to the bis-trioxane bis-trioxane
tertiary alcohol isopropyl sulfonate 39 and the method of
converting bis-trioxane ketone 7 to the bis-trioxane tertiary
alcohol N,N-dimethylsulfonamide 40 of the present invention.
FIG. 45 schematically
depicts the method of converting bis-trioxane vicinal diol 5 to
the bis-trioxane vicinal diol cyclic carbonate 41 and the method
of converting bis-trioxane vicinal diol 5 to the bis-trioxane
vicinal diol cyclic sulfate 42 of the present invention.
FIG. 46 schematically
depicts the method of converting bis-trioxane epoxide 6 to the
bis-trioxane tertiary alcohol pyridine sulfide 43 of the present
invention.
FIG. 47 schematically
depicts the method of converting bis-trioxane ketone 7 to the
bis-trioxane ketone O-TMS cyanohdrin 44 and the method of
converting bis-trioxane ketone 7 to the bis-trioxane tertiary
alcohol nitrile 45 of the present invention.
FIG. 48 schematically
depicts the method of converting bis-trioxane ketone 7 to the
bis-trioxane methyl enol ether 46 of the present invention.
FIG. 49 schematically
depicts the method of converting bis-trioxane methyl enol ether 46
to the bis-trioxane aldehyde 47 of the present invention.
FIG. 50 schematically
depicts the method of converting bis-trioxane aldehyde 47 to the
bis-trioxane aniline 48 of the present invention.
FIG. 51 schematically
depicts the method of converting bis-trioxane primary alchol 4 and
bis-trioxane diol 5 to a number of compounds according to the
present invention. In cases where the derivatization of
bis-trioxane primary alcohol 4 is shown, conversion of
bis-trioxane secondary alcohol 17 and bis-trioxane diol 5 to their
corresponding analogs is also in accordance with the present
invention.
FIG. 52 schematically
depicts the method of converting a number of compounds of the
present invention to ten other compounds that can be synthesized
according to the present invention.
FIG. 53 schematically
depicts the method of converting bis-trioxane aldehyde 47 to a
range of substituted and unsubstituted amine/amide derivatives of
the current invention.
FIG. 54 represents other
compounds that can be synthesized according to the present
invention.
DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENT
The present invention provides a direct method for converting a
novel C-10-carba trioxane dimer in one step into a number of
different dimers, all of which are hydrolytically stable. The
resulting trioxane dimers may then be further reacted to form
3-carbon atom linked, oxygenated dimers. These C-10 non-acetal
derivatives of natural trioxane artemisinin have high in vitro
antimalarial and antitumor activities.
In general, the compound of the present invention includes
resolved enantiomers, diastereomers, solvates and pharmaceutical
acceptable salts thereof, and may be illustrated as follows:
##STR00005##
Where if R.sub.1 is hydrogen or OH then R.sub.2 is AX, and if
R.sub.2 is hydrogen or OH then R.sub.1 is AX, and A may be absent
or A may be any alkyl or aryl group where X is hydrogen, a
phosphate group, a phosphonic acid derivative group, an alcohol
group, a carboxylic acid group, an ether group, an ester group, a
nitrile group, a sulfone group, a sulfide group, an amino acid
derivative group, an amine group, and amide group, an aldehyde
group, or an aromatic group.
The alcohol group may be represented by --R.sup.3OH, where R.sup.3
is a straight chained or branched alkyl group having 1 to 5 carbon
atoms. The carboxylic acid group may be represented by
--R.sup.4COOH, where R.sup.4 is at least one saturated or
unsaturated alkyl group, an ester group, an ether group or a
combintion thereof. When R.sup.4 is an ester group, it may be
represented by --R.sup.5COO--, where R.sup.5 is bonded to the
carboxylic acid group and has 0 to 5 carbon atoms. When R.sup.4 is
an ether group, it may be represented by R.sup.6--O--R.sup.7
wherein R.sup.6 and R.sup.7 are, independently, an alkyl or allyl
group having 0 to 5 carbon atoms. The aromatic group may be
represented by Ar--(R.sup.8).sub.m, where Ar represents a benzene
ring, and m is 1 or 2, and R.sup.8 may represent
--CH.dbd.CH.sub.2, or --COOH. The ester group may be represented
by --CR.sup.9, where R.sup.9 is an ester of nicotinic acid, an
ester of isonicotinic acid, or the ester group is represented by
--CO(C.dbd.O)R.sup.9a, where R.sup.9a is Ph(CY.sub.3).sub.o, where
o is 1 or 2, and Y may be, independently, H, F, Cl, Br, or 1, or
where R.sup.9a is a substituted heterocyclohexane compound. The
phosphonic acid derivative group may be represented by
--CO--P(R.sup.10)OOH, where R.sup.10 is an alkyl group having 0 to
5 carbon atoms. The phosphate group is --COP(O)(OR.sup.11).sub.2,
where R.sup.11 is an alkyl group having 0 to 5 carbon atoms, or a
phenyl group. The nitrile group is R.sup.12CN, where R.sup.12 is
an alkyl group having 0 to 5 carbon atoms. The sulfone group may
be represented by --CS(.dbd.O).sub.2R.sup.13, wherein R.sup.13 is
--N(CH.sub.3).sub.2, --OR.sup.14, or --Ph--COOR.sup.14, where
R.sup.14 is H, CH.sub.3, or --CH(CH.sub.3).sub.2. The sulfide
group may be represented by --CSR.sup.15, where R.sup.15 is
pyridine or --Ph--COOR.sup.16, where R.sup.16 is H or CH.sub.3.
The amino acid derivative group is
--COC(.dbd.O)CN(R.sup.17).sub.2, where each R.sup.17 group is,
independently, H or CH.sub.3. The amine group may be represented
by --CN(R.sup.18).sub.2, where each R.sup.18 group is,
independently, H, an alkyl group, or a phenyl group. The ether
group may be represented by --C--O--CR.sup.19, where R.sup.19 is a
substituted pyridine. The amide group is
--(C.dbd.O)N(R.sup.20).sub.2, or
--CH.sub.2(C.dbd.O)N(R.sup.20).sub.2 where each R.sup.20 is,
independently, H or --CH.sub.2CH.sub.2N(CH.sub.3).sub.2.
The compound of the present invention may also be illustrated as:
formula:
##STR00006## where D forms a heterocyclic ring having 3 to 5
atoms. For example, the heterocyclic ring may be a 3-membered ring
and one of the atoms in the ring is oxygen. The heterocyclic ring
may also be a 5-membered ring and two of the atoms in the ring are
oxygen, and the ring may also be substituted with an oxygen atom
and another atom in the 5-membered ring may be a sulfur or
phosphorus atom. In another example, the 5-membered ring may also
be substituted with 1 or 2 oxygen atoms bonded to the sulfur atom.
The compound of the present invention may further be illustrated
as:
##STR00007## where where E is H, O, NR, CH.sub.2 or S wherein R
may be hydrogen, alkyl, aryl or any other substituent.
In general, the first step of the preferred process of the present
invention, shown in FIG. 1, conversion of artemisinin (I) into
.alpha.-dihydroartemisinin acetate (2), is accomplished by using
an effective amount of a hydride nucleophile in combination with
an acetylating agent which chemoselectively reacts at the C-10
position of the artemisinin skeleton without disrupting the O--O
bond in this trioxane. Effective nucleophilic hydride reagents
include, but are not limited to sodium borohydride, and DIBAL. The
relative amounts of the various possible nucleophilic hydride
reagents depends upon the concentration employed and other
conditions of the reaction. Various amounts of the nucleophilic
reagents can be employed, but generally it should be present in
the range of 1.0 to 1.5 molar equivalents of nucleophilic hydride
per molar equivalent of artemisinin for the reaction to proceed to
completion. Effective acetylating agents include, but are not
limited to acetyl chloride and acetic anhydride. The relative
amounts of the various possible acetylating agents depends upon
the concentration employed and other conditions of the reaction.
Various amounts of the acetylating agents can be employed, but
generally it should be present in the range of 1.0 to 1.5 molar
equivalents of acetylating agent per molar equivalent of
dihydroartemisinin for the reaction to proceed to completion.
The next step, shown in FIG. 2, in the production of the novel
meso trioxane dimer 3 involves the substitution of the acetoxy
group from the C-10 acetate 2 product to form the meso trioxane
dimer 3 product. Inspiration for this bis-allylation of C-10
acetate 2 was based on the pioneering trioxane mono-allylations of
Ziffer (Pu, Y. M.; Ziffer, H., Synthesis and Antimalarial
Activities of 12.beta.-Allyldeoxoartemisinin. J. Med. Chem. 1995,
38, 613-616) and O'Neill (O'Neill, et al., J. Med. Chem. 1999, 42,
5487-5493; and O'Neill, P. M., et al., J. Chem. Soc., Perkin
Trans. 2001, 1, 2682-2689.) using allylsilane and based also on
allylic bis-silane chemistry, see Rychnovsky, S. D., et. al.,
Tetrahedron Lett. 1999, 40, 41-44. The requisite allylic
bis-silane is easily prepared in one step from the corresponding
commercial allylic dichloride (Shown in FIG. 2); in the presence
of fresh tin tetrachloride, the allylic bis-silane converts
acetate 2 on gram scale into meso dimer 3, characterized by
.sup.1H NMR spectroscopy as done before in structurally related
trioxanes. This double substitution reaction undoubtedly proceeds
sequentially via initial monoallylation, producing an intermediate
C-10 allylic silane that then reacts with another molecule of
trioxane acetate 2 to form the product dimer 3. This new dimer 3,
with an unsaturated 3-carbon atom linker between the two trioxane
units, is stable in air and light at room temperature for at least
six months, and its preparation on much larger industrial scale
should be feasible.
In contrast to most simple peroxides that are easily cleaved by
reducing agents and by reactive organometallics, the peroxide
linkage in artemisinin-like trioxanes is relatively robust.
Therefore, several different chemical transformations
chemospecifically involving only the linker isobutylene
carbon-carbon double bond in dimer 3 may be performed and are
discussed in further detail below.
Borane reduction and in situ oxidation produced bis-trioxane
primary alcohol 4, shown in FIG. 3. Dihydroxylation using osmium
tetroxide gave bis-trioxane vicinal diol 5, shown in FIG. 4.
Dimethyldioxirane formed bis-trioxane epoxide 6, shown in FIG. 5.
Oxidative cleavage using catalytic osmium tetroxide and Oxone led
to bis-trioxane ketone 7, shown in FIG. 6. Bis-Trioxanes 4-7 are
stable even when heated neat in air for 24 h at 60.degree. C.;
.sup.1H NMR spectroscopy showed less than 5% decomposition under
these accelerated aging conditions.
To illustrate further the chemical inertness of the peroxide unit
in these trioxane dimers, and especially to generate some
water-soluble dimers that can be easily administered in vivo, each
dimer 4-7 was converted into a carboxylic acid (FIGS. 16-20).
Primary alcohol 4 opened succinic anhydride to form bis-artesunate
8a in high yield, see FIG. 16. Likewise, diol 5 opened succinic
anhydride to produce the tertiary alcohol primary succinate ester
9, see FIG. 17. Epoxide 6 reacted chemospecifically with a
benzenethiol in the presence of chromatographic alumina to give
.beta. hydroxysulfide 10a in high yield; sulfide to sulfone
oxidation gave dimer benzoate ester 10b that was saponified into
benzoic acid 10c, see FIG. 18. Ketone 7 underwent chemospecific
addition of styryllithium to afford styryl tertiary alcohol 11a;
oxidative cleavage of the styrene double bond produced benzoic
acid 11b, see FIG. 19. Primary alcohol 4 was allylated and the
allyl double bond was oxidatively cleaved to generate acetic acid
12b, see FIG. 20.
Each of these new carboxylic acid dimers is at least as soluble in
water at pH 7.4 as is the antimalarial drug candidate artelinic
acid, and tertiary alcohol primary succinate ester 9 is close to
30 times more water-soluble than artelinic acid, and phosphonic
acid 16 is even more water soluble than succinate ester 9.
Trioxane dimer carboxylic acids 8a-10c and 12b are stable in air
even at 60.degree. C. for 24 hours.
Primary alcohol 4 may also be transformed into a variety of other
compounds as shown in FIGS. 21-25, 28, 30, 34-38 and 43. Likewise,
diol 5 may be converted into a variety of compounds as shown in
FIGS. 27, 29, 31 and 45. Additionally, secondary alcohol 17 may be
transformed into a variety of compounds as shown in FIGS. 32 and
33. Likewise, ketone 7 may be converted into a variety of
compounds as shown in FIGS. 42, 44, 47 and 48 and epoxide 6 may be
reacted further as shown in FIG. 46. Finally, dimer 3 may be
converted to a variety of compounds as shown in FIGS. 51, 52 and
53.
Determination of Antimalarial
Activity
To determine the antimalarial effect of various dimers of the
present invention, screening assays were performed against
chloroquine-sensitive P. falciparum (NF54), according to the
method described below, and their IC.sub.50 values are included in
Table 1.
Activity was determined by measuring the incorporation of
[.sup.3H]hypoxanthine, by the methods of DesJardins and Milhous,
with the following modifications, see Desjardins, R. E.; Canfield,
C. J.; Haynes, J. D.; Chulay, J. D., Antimicrob. Agents
Chemother., 16:710 (1979); Milhous, W. K.; Weatherly, N. F.;
Bowdre, J. H.; Desjardins, R., Antimicrob. Agents Chemother.,
27:525 (1985). Chloroquine-sensitive P. falciparum (NF54 strain)
were maintained in a 2.4% suspension of type O.sup.+ human
erythrocytes (obtained weekly from a rotating pool of screened
healthy volunteers) in RPMI 1640 (Gibco BRL # 13200-076),
supplemented with 25 mM
N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES;
Calbiochern #391338), 27 mM NaHCO.sub.3 (Gibco BRL # 11810-025),
and 10% heat-inactivated human type O.sup.+ serum (Interstate
Blood Bank, Inc.), under 3% O.sub.2, 4% CO.sub.2, and 93% N.sub.2.
Parasitemia was maintained at 0.05-3% and doubling time at
approximately 15 hours by twice weekly change of medium and
replenishment with fresh erythrocytes.
Stock solutions (approximately 2.5 mg/mL of HPLC-purified or
recrystallized test compound) were prepared in dimethyl sulfoxide
(DMSO; Sigma-Aldrich #27,043-1). DMSO solutions were diluted
500-fold in medium, serially diluted in 0.2% DMSO in medium (to
maintain constant solvent concentration), then 100 .mu.L aliquots
were pipetted into microtiter plate wells (Costar3595).
Provisional EC.sub.50 values were obtained in a survey of seven
5-fold dilutions yielding final concentrations (in triplicate) of
0.16-2500 ng/mL. Assays were later expanded to include ten
concentrations (in quadruplicate) of approximately 1.8-fold
dilutions which flank the provisional EC.sub.50. Plates included
at least 8 wells of no drug controls (4 with and 4 without DMSO)
and 4 wells of uninfected erythrocytes. Parasite culture (0.25%
parasitemia in 2.4% hematocrit; 100 .mu.L per well) was added and
the plate was incubated for 48 hours prior to the addition of 25
.mu.L [.sup.3H]hypoxanthine (14.1 Ci/mmol, 1 mCi/mL in 70%
ethanol, New England Nuclear NET-177, diluted to 25 .mu.Ci/mL with
medium) and subsequent 20 hour incubation. Cells were harvested
(Brandel MB-48R) onto GF-C glass filters (Brandel). The filters
were washed five times with 3 mL water per sample spot, dried
under a heat lamp, and counted (Beckman Model LS-6500) in
scintillation cocktail (ICN Cytoscint).
Decays per minute (dpm) values were downloaded and analyzed (Power
Macintosh 7200/90; Microsoft Excel 5.0), to yield the mean and
standard deviation at each drug concentration. Dose-response
curves were fit to the experimental data (Delta Point DeltaGraph
3.5.3) by means of the Marquardt algorithm, were solved for the
drug concentration that kills 50% of parasites, and were analyzed
for goodness of fit (R.sup.2 value).
TABLE-US-00001 TABLE I Antimalarial Activities in vitro.sup.a
Trioxane IC.sub.50(nM) 3 24.0 4 0.87 5 0.59 6 2.8 7 0.91 8a 2.0 8b
1.7 9 3.0 10c 2.4 11b 2.1 12b 3.2 13 0.53 14 10.0 15 0.58 16 320
17 0.66 18 0.34 19 2.4 21 4.4 23 0.40 24 0.42 25 0.31 26 0.74 27
0.48 32 1.1 33 0.81 35 2.0 36 1.7 37 2.8 38 200 40 0.73 41 0.59 42
19 48 4.8 Artemisinin 9.2 .+-. 1.7 .sup.aThe standard deviation
for each set of quadruplicates was an average of 8.6%
(.ltoreq.22%) of the mean. R.sup.2 values for the fitted curves
were .gtoreq.0.933. Artemisinin activity is mean .+-. standard
deviation of concurrent control (n = 34).
In sharp contrast to the potency of the natural trioxane
artemisinin (IC.sub.50=7.7 nm) and of the initial olefinic dimer 3
(IC.sub.50=24 nM), alcohol dimers 4 and 17, diol dimer 5 and
ketone dimer 7 all have substantially enhanced potencies, with
IC.sub.50 values below one nM. In addition, further derivitization
of these potent antimalarials has produced a number of analogs
also antimalarially active in sub-nanomolar concentrations (most
notably: pyridine N-oxides 13, 15, 18, 23, 24 and 25, phosphoric
acid triesters 26 and 27, sulfonamide 40 and cyclic carbonate 41).
The in vivo antimalarial efficacies of water-soluble dimer
carboxylic acids 8a-10c and 12b (11b not tested), as measured in
mice according to a published protocol, are shown in Table II. In
all cases, these water-soluble dimeric trioxanes are more
efficacious than the drug candidate artelinic acid administered
intravenously (IV) and than the clinically used drug sodium
artesunate administered orally (PO). At an IV dose of 10 mg/kg of
mouse body weight, each dimeric trioxane 8a-10c and 12b suppressed
P. berghei NY malaria parasite growth considerably better
(>80%) than did artelinic acid or sodium artesunate. Neither
overt toxicity nor behavioral modification was observed due to
drug administration in any of these mouse experiments.
TABLE-US-00002 TABLE II Antimalarial Efficacies in vivo % Parasite
Trioxane Administration Supression Carboxylic Acid Route
ED.sub.50.sup.b ED.sub.90.sup.b at 10 mg/kg 8a IV 2.2 6.3 81.0 PO
9.0 15.0 79.2 12b IV 1.0 3.5 95.7 PO 6.5 17.0 46.5 Artelinic Acid
IV 11.0 25.0 54.7 Sodium Artesunate PO 10.0 39.0 52.8 9 IV 2.4
11.0 83.4 PO 4.8 34.0 55.4 10c IV 2.7 10.0 83.4 PO 7.5 35.0 46.1
Artelinic Acid IV 5.6 43.0 42.4 Sodium Artesunate PO 5.5 70.0 50.9
.sup.bmg/kg .times. 4
Determination of Antitumor
Activities
Growth Inhibition. To determine the growth inhibition (GI) and
cytotoxicity of dimers 4, 5, 8a, 9, 10c, 11b, 12b, 13, and 14
respectively, of the present invention, screening assays were
performed by the National Cancer Institute using a 60 cell line
panel; these activities are summarized in Tables III, IV and V
(set out below). The screening assay is performed on 96-well
microtitre plates. Relatively high initial inoculation densities
are used, in order to permit measurement of "time-zero" values and
to enhance the screen's ability to detect and provide some
differentiation between growth inhibition and cytotoxic response
parameters. The specific inoculation densities (which range from
5,000 to 40,000 cells/well) used for each cell line are those
which, for the respective line, were determined to give an optical
density signal for both the "time-zero" value (at 24 hours) and
the "no-drug" control (at 72 hours) above the noise level and
within the linear range of the end-point assay (which measures
cellular protein). The inoculated microtitre plates are
pre-incubated for 24 hours at 37.degree. C. prior to drug
additions. The five drug dilutions tested routinely range from
10.sup.-4 to 10.sup.-8 molar. Higher or lower concentration ranges
may be selected on a non-routine basis if appropriate solubility
and/or prior biological information or other screening data so
dictate. Duplicate wells are prepared for all concentrations,
(concentration is often denoted by placing brackets around a
number); "time-zero" and "no drug" controls are also provided for
each test. The minimum amount of compound required for a one-time
evaluation in the routine screen can be calculated from the
knowledge that each test requires a total of approximately 40 ml
(0.04 liter) of cell culture medium containing the highest desired
drug concentration. Thus, the amount (grams) of sample required
(assuming an upper test concentration limit of 10.sup.-4 M) is:
molecular weight of compound.times.10.sup.-4.times.0.04. After a
48 hour incubation (37.degree. C.) with the test compound, the
cells are fixed in situ to the bottoms of the microtitre wells by
addition of 50 .mu.l of either 50% trichloroacetic acid (for
adherent cell lines) or 80% trichloroacetic acid (for settled cell
suspension lines), followed by incubation for 60 minutes at
4.degree. C. The cellular protein in each well is assayed using a
sulforhodamine B (SRB) stain procedure. Briefly, after discarding
the supernatants, the microtitre plates are washed 5 times with
deionized water and air-dried. One hundred microliters of SRB
solution (0.4% w/v in 1% acetic acid) is added to each microtitre
well and incubated for 10 minutes at room temperature. Unbound SRB
is removed by washing 5 times with 1% acetic acid. The plates are
air-dried, the bound stain is solubilized with Tris buffer, and
the optical densities read at 515 nm. SRB is a bright pink anionic
dye which, in dilute acetic acid, binds electrostatically to the
basic amino acids of TCA-fixed cells. Cryopreserved master stocks
of all the lines are maintained, and cultures used for screening
are replaced from the master stock after no more than twenty
passages in the screening laboratory. The cell line panel consists
of 60 lines, organized into nine, disease-related subpanels
including leukemia, non-small-cell lung cancer, colon, CNS,
melanoma, ovarian, renal, prostate and breast cancers.
The response parameters GI.sub.50 and LC.sub.50 are interpolated
values representing the concentrations at which the percentage
growth (PG) is +50 and -50, respectively:
GI.sub.50 is the concentration for which the PG=+50. At this value
the increase from time t.sub.zero, in the number or mass of cells
in the test well is only 50% as much as the corresponding increase
in the control well during this period of the experiment, see
Table III. A drug effect of this intensity is interpreted as
primary growth inhibition.
TGI is the concentration for which PG=0. At this value the number
or mass of cells in the well at the end of the experiment equals
the number or mass of cells in the well at time t.sub.zero, see
Table IV. A drug effect of this intensity is regarded as
cytostasis.
LC.sub.50 is the concentration for which the PG=-50. At this
value, the number or mass of cells in the test well at the end of
the experiment is half that at time t.sub.zero, see Table V. This
is interpreted as cytotoxicity.
TABLE-US-00003 TABLE III Log.sub.10GI.sub.50 Panel/Cell Artem-
Trioxane Dimers Pacli- Line isinin 4 5 8a 9 10c 11b 12b 13 14
taxel Leukemia CCRF-CEM -- -- -4.71 <-8.30 <-8.30 <-8.30
-8.07 <-8.30 5.73 &g- t;-4.30 -11.61 HL-60(TB) -4.26 -7.78
<-8.00 <-8.30 <-8.30 <-8.30 <-8.30 &l- t;-8.30
<-8.30 -11.57 K-562 -4.33 -7.91 <-8.00 <-8.30 -8.30
<-8.30 <-8.30 <-8.30 - <-8.30 -10.83 MOLT-4 -4.73
-7.92 <-8.00 -8.18 -5.15 -- <-8.30 -7.66 -- -11.07 RPMI-8226
>-4.00 <-8.00 -- <-8.30 <-8.30 <-8.30 -- -- <--
8.30 <-8.30 <-13.00 SR >-4.00 <-8.00 -- -- -- -- -- --
-- -- 8.34 Non-Small Cell Lung Cancer A549/ATCC -4.17 -7.29 -7.59
-4.42 -4.86 -5.28 -5.69 >-4.30 -5.98 <-8- .30 -- EKVX
>-4.00 -7.12 -- -6.90 -- -4.99 -4.79 >-4.30 -8.19 <-8.30
-- HOP-62 >-4.00 -4.92 -4.66 -6.34 -5.69 <-8.30 -6.96 -6.23
-- -4.90 -9- .67 HOP-92 >-4.00 -6.37 -4.93 -6.56 <-8.30
<-8.30 -7.43 -7.00 -8.04 &- lt;-8.30 -- NCI-H226 >-4.00
-4.82 -4.87 <-8.30 -- <-8.30 -- -- -- -- -- NCI-H23
>-4.00 -7.84 -4.83 <-8.30 <-8.30 <-8.30 -8.19
<-8.3- 0 <-8.30 <-8.30 -- NCI-H322M -- -4.97 -4.71 -5.11
-5.07 -6.03 -6.72 -5.03 -6.26 <-8.30 -10- .12 NCI-H460
>-4.00 -7.35 -5.02 <-8.30 <-8.30 <-8.30 <-8.30
<- ;-8.30 <-8.30 <-8.30 -12.16 NCI-H522 -- -7.53 -7.33
-6.16 -4.91 <-8.30 -6.54 >-4.30 -- -- <-1- 3.00 Colon
Cancer COLO 205 >-4.00 <-8.00 <-8.00 <-8.30 --
<-8.30 <-8.30 &l- t;-8.30 <-8.30 <-8.30 -11.07
HCC-2998 >-4.00 -7.45 -4.65 -- -- -- -- -- -- -- -12.34 HCT-116
-4.18 <-8.00 -4.72 <-8.30 <-8.30 <-8.30 <-8.30
<- -8.30 <-8.30 <-8.30 <-13.00 HCT-15 >-4.00
<-8.00 -5.28 <-8.30 <-8.30 <-8.30 <-8.30 &-
lt;-8.30 <-8.30 <-8.30 -6.37 HT29 >-4.00 -7.75 <-8.00
<-8.30 <-8.30 <-8.30 <-8.30 <- ;-8.30 -- --
<-13.00 KM12 >-4.00 <-8.00 <-8.00 <-8.30 <-8.30
<-8.30 <-8.30- <-8.30 <-8.30 -- -11.43 SW-620
>-4.00 <-8.00 -4.97 -- -- -- -- -- <-8.30 <-8.30
-11.60- CNS Cancer SF-268 -- -5.40 -4.94 -7.11 -5.48 <-8.30
-7.72 -6.82 -5.29 -- -- SF-295 -- -5.59 -4.94 -- <-8.30 -- --
-- -5.21 <-8.30 -- SF-539 -- -7.05 -4.86 -5.27 -4.90 -5.19
-4.80 -4.53 <-8.30 <-8.30 -1- 1.09 SNB-19 >-4.00 -4.88
-4.82 -5.62 -- -6.72 -6.53 -6.03 -5.08 -- -8.98 SNB-75 >-4.00
-4.99 -4.53 -6.47 -- -- -7.40 -- -- -- -- U251 >-4.00 -7.27
-7.68 -8.20 -- <-8.30 <-8.30 <-8.30 <-8.3- 0 <-8.30
-11.29 Melanoma LOX IMVI -- -7.26 <-8.00 -- -- -- -- --
<-8.30 <-8.30 -11.80 MALME-3M -- -7.31 -- <-8.30
<-8.30 <-8.30 <-8.30 -- <-8.30 - -7.22 -- M14 -- -5.87
-4.59 -6.94 -- <-8.30 -7.81 -6.68 -5.81 -- -11.73 SK-MEL-2 --
-7.33 -4.94 -5.12 -4.88 -- -6.43 -5.62 -5.12 >-4.30 -9.53
SK-MEL-28 >-4.00 -4.95 -4.79 -6.09 <-8.30 -5.45 -6.40 -4.92
-5.13 --- -- SK-MEL-5 >-4.10 -7.90 -7.69 -- -- -- -- --
<-8.30 <-8.30 -- UACC-257 >-4.00 -7.31 <-8.00 -5.02
-4.89 -- -- >-4.30 -5.15 <-- 8.30 -10.30 UACC-62 >-4.00
-6.86 -- -- -- -- -- -- -8.00 <-8.30 -10.46 Ovarian Cancer
IGROVI -4.31 -5.36 -4.97 -5.07 -4.97 -- -5.98 -5.06 -5.36 -5.81
-8.61 OVCAR-3 -- -7.68 -5.09 <-8.30 <-8.30 <-8.30
<-8.30 <-8.30 -- 7.75 <-8.30 -10.40 OVCAR-4 -- -5.44
-4.99 -- -- -- -- -- <-8.30 <-8.30 -5.00 OVCAR-5 >-4.00
-7.79 -4.78 <-8.30 <-8.30 <-8.30 <-8.30 <- -8.30
<-8.30 <-8.30 -9.38 OVCAR-8 >-4.00 -7.33 <-8.00
>-4.30 -5.12 -5.25 -5.26 >-4.30 -7- .69 <-8.30 -10.75
SK-OV-3 -- -4.85 -4.62 -4.89 -- -6.82 -- >-4.30 -5.13 >-4.30
-- Leukemia CCRF-CEM -- -- -4.71 <-8.30 <-8.30 <-8.30
-8.07 <-8.30 5.73 &g- t;-4.30 -11.61 HL-60(TB) -4.26 -7.78
<-8.00 <-8.30 <-8.30 <-8.30 <-8.30 &l- t;-8.30
<-8.30 -11.57 K-562 -4.33 -7.91 <-8.00 <-8.30 -8.30
<-8.30 <-8.30 <-8.30 - <-8.30 -10.83 MOLT-4 -4.73
-7.92 <-8.00 -8.18 -5.15 -- <-8.30 -7.66 -- -11.07 RPMI-8226
>-4.00 <-8.00 -- <-8.30 <-8.30 <-8.30 -- -- <--
8.30 <-8.30 <-13.00 SR >-4.00 <-8.00 -- -- -- -- -- --
-- -- 8.34 Non-Small Cell Lung Cancer A549/ATCC -4.17 -7.29 -7.59
-4.42 -4.86 -5.28 -5.69 >-4.30 -5.98 <-8- .30 -- EKVX
>-4.00 -7.12 -- -6.90 -- -4.99 -4.79 >-4.30 -8.19 <-8.30
-- HOP-62 >-4.00 -4.92 -4.66 -6.34 -5.69 <-8.30 -6.96 -6.23
-- -4.90 -9- .67 HOP-92 >-4.00 -6.37 -4.93 -6.56 <-8.30
<-8.30 -7.43 -7.00 -8.04 &- lt;-8.30 -- NCI-H226 >-4.00
-4.82 -4.87 <-8.30 -- <-8.30 -- -- -- -- -- NCI-H23
>-4.00 -7.84 -4.83 <-8.30 <-8.30 <-8.30 -8.19
<-8.3- 0 <-8.30 <-8.30 -- NCI-H322M -- -4.97 -4.71 -5.11
-5.07 -6.03 -6.72 -5.03 -6.26 <-8.30 -10- .12 NCI-H460
>-4.00 -7.35 -5.02 <-8.30 <-8.30 <-8.30 <-8.30
<- ;-8.30 <-8.30 <-8.30 -12.16 NCI-H522 -- -7.53 -7.33
-6.16 -4.91 <-8.30 -6.54 >-4.30 -- -- <-1- 3.00 Renal
Cancer 786-0 >-4.00 -7.48 -4.87 -6.45 <-8.30 <-8.30 -7.17
-6.59 -7.81 &l- t;-8.30 -8.01 A498 >-4.00 -6.69 -4.81 -- --
-- -- -- -6.97 -7.20 -7.14 ACHN >-4.00 -7.12 <-8.00 -- -6.67
-- -- -- <-8.30 <-8.30 -- CAKI-1 -- -7.05 -4.94 -6.84 --
<-8.30 -7.74 -6.91 -7.36 <-8.30 -- RXF 393 -4.08 -4.80 -4.89
<-8.30 -7.67 <-8.30 <-8.30 <-8.30 -5- .20 -- -8.32
SN12C -4.21 -7.46 -7.60 -- -- -- -- -- <-8.30 <-8.30 -9.53
TK-10 >-4.00 -6.60 -4.91 -6.92 <-8.30 <-8.30 -7.81 -7.22
<-8.3- 0 <-8.30 -7.89 UO-31 -4.06 -7.46 -7.38 -5.46 -5.05
-5.91 -6.78 -5.84 <-8.30 <-8.30 - -6.09 Prostate Cancer PC-3
-4.17 <-8.00 <-8.00 <-8.30 <-8.30 <-8.30 <-8.30
<- ;-8.30 <-8.30 <-8.30 -10.85 DU-145 -- -6.24 -4.83
-- -- -- -- -- -7.48 -- -9.38 Breast Cancer MCF7 >-4.00 -7.22
<-8.00 <-8.30 <-8.30 <-8.30 <-8.30 -7.- 37
<-8.30 <-8.30 -11.69 NCI/ADR-RES -- -7.45 -4.75 -5.64 -5.61
-5.73 -6.84 -6.45 -7.60 -6.07 -8.48- MDA- -4.20 -5.40 -4.99 -7.19
-- <-8.30 -- -- -7.64 <-8.30 -8.54 MB231/ATCC HS 578T
>-4.00 -4.82 -4.72 >-4.30 -4.36 -4.82 -5.15 >-4.30
<-8- .30 <-8.30 -- MDA-MB-435 -- -7.50 -- -- <-8.30
<-8.30 -8.16 -6.97 -7.62 <-8.30 - <-13.00 MDA-N >-4.00
-7.54 -- -7.29 -- -- -- -- -- <-13.00 BT-549 -4.06 -7.11
<-8.00 -7.91 -- -6.67 -5.82 -- <-8.30 <-8.30 -- 9.31
T-47D -- <8.00 -7.23 <-8.30 -- <-8.30 <-8.30 <-8.30
<-8.- 30 -- -9.81 MG MID -- -6.87 -5.97 -7.01 -7.02 -7.57 -7.37
-6.73 -7.38 -7.79 -- Delta -4.07 1.13 2.03 1.29 1.28 -0.73 0.93
1.57 0.92 -.51 -10.15 Range 0.73 3.20 3.47 4.00 3.94 3.48 3.52
4.00 3.22 4.00 8.00
TABLE-US-00004 TABLE IV Log.sub.10TGI.sub.50 Panel/Cell Artem-
Trioxane Dimers Pacli- Line isinin 4 5 8a 9 10c 11b 12b 13 14
taxel Leukemia CCRF-CEM -- -4.66 >-4.00 >-4.30 >-4.30
-4.84 >-4.30 >-4.30 - >-4.30 >-4.30 >-4.00
HL-60(TB) >-4.00 -4.88 -- -7.61 -- <-8.30 -8.11 <-8.30 --
>-4.- 30 -4.53 K-562 >-4.00 >-4.00 >-4.00 >-4.30
>-4.30 -4.75 >-4.30 &g- t;-4.30 -- >-4.30 >-4.00
MOLT-4 >-4.00 >-4.00 >-4.00 >-4.30 >-4.30 >-4.30
>-4.- 30 >-4.30 -- -- >-4.00 RPMI-8226 >-4.00 -6.91
>-4.00 -6.19 >-4.30 -5.03 -- -- >-4.30 - >-4.30
>-4.00 SR >-4.00 -4.58 -- -- -- -- -- -- -- >-4.30
>-4.00 Non-Small Cell Lung Cancer A549/ATCC >-4.00 -4.71
-4.82 >-4.30 >-4.30 >-4.30 >-4.30 &g- t;-4.30
-4.61 >-4.30 -- EKVX >-4.00 -4.77 -- -5.47 -- -4.63
>-4.30 >-4.30 -5.08 >-4.30- -- HOP-62 >-4.00 -4.56
-4.26 >-4.30 >-4.30 -5.01 >-4.30 >-4.30- -4.91
>-4.30 -4.80 HOP-92 >-4.00 -4.65 -4.49 >-4.30 >-4.30
-5.05 >-4.30 >-4.30- -5.27 >-4.30 -- NCI-H226 >-4.00
-4.40 -4.49 -6.67 -- <-8.30 -- -- -- -- -- NCI-H23 >-4.00 --
-4.26 >-4.30 -4.65 -5.25 -4.63 >-4.30 -5.17 -- - --
NCI-H322M -- -4.63 -4.44 >-4.30 >-4.30 -4.98 >-4.30
>-4.30 -5.- 06 >-4.30 -4.46 NCI-H460 >-4.00 -4.71 -4.40
>-4.30 >-4.30 -5.11 >-4.30 >-4.- 30 -4.92 >-4.30
-4.92 NCI-H522 -- -4.88 -4.59 >-4.30 >-4.30 -4.34 >-4.30
>-4.30 -4.6- 0 >-4.30 -11.20 Colon Cancer COLO 205 >-4.00
-6.43 -4.87 -6.29 -- <-8.30 -6.99 -5.28 >-4.30 --- --
HCC-2998 >-4.00 -5.39 -4.23 -- -- -- -- -- -4.91 -5.33 -4.77
HCT-116 >-4.00 -- >-4.00 >-4.30 >-4.30 -5.16 -4.40
>-4.30 -- 5.06 >-4.30 -4.82 HCT-15 >-4.00 -4.78 -4.53
-5.61 -5.01 -5.23 -6.70 -5.00 -8.19 -4.96 >- ;-4.00 HT29
>-4.00 -4.67 >-4.00 >-4.30 4.91 >-4.30 >-4.30
>-4.3- 0 -- -- -- KM12 >-4.00 -4.79 -4.47 <-8.30
<-8.30 <-8.30 <-8.30 <-8.- 30 -5.04 >-4.30 -4.36
SW-620 >-4.00 -4.89 >-4.00 -- -- -- -- -- -5.05 >-4.30
>-4.00 CNS Cancer SF-268 -- -4.63 -4.53 >-4.30 >-4.30
-5.14 >-4.30 >-4.30 -4.80 - >-4.30 -- SF-295 -- -4.80
-4.49 -- <-8.30 -- -- -- -4.77 >-4.30 -- SF-539 -- -4.72
-4.41 >-4.30 -4.50 -4.66 >-4.30 >-4.30 -- -- -- SNB-19
>-4.00 -4.50 -4.34 >-4.30 -- -4.96 >-4.30 >-4.30
>-4- .30 -- >-4.00 SNB-75 >-4.00 -4.55 -4.04 >-4.30
>-4.30 -4.80 >-4.30 >-4.30- -- -- -- U251 >-4.00 -4.47
-4.61 >-4.30 -4.75 -5.22 -7.39 >-4.30 -5.08 >- ;-4.30
-4.32 Melanoma LOX IMVI -- -4.45 -5.47 -- -- -- -- -- <-8.30
<-8.30 -4.65 MALME-3M -4.06 -4.74 -4.50 -6.82 -5.14 <-8.30
-7.46 -6.40 <-8.30 -- - -4.46 M-14 >-4.00 -4.68 >-4.00
>-4.30 >-4.30 -4.91 >-4.30 >-4.- 30 -4.75 >-4.30
-4.62 SK-MEL-2 >-4.00 -4.92 -4.53 >-4.30 >-4.30 >-4.30
>-4.30 >- ;-4.30 >-4.30 >-4.30 -- SK-MEL-28
>-4.00 -4.54 -4.31 >-4.30 >-4.30 -4.63 >-4.30 >-4-
.30 -4.73 >-4.30 -- SK-MEL-5 >-4.00 -7.18 -4.64 -- -- -- --
-- -5.28 -6.49 -- UACC-257 >-4.00 -4.71 -4.90 >-4.30
>-4.30 -4.38 >-4.30 >4.3- 0 -4.65 >-4.30 -4.52 UACC-62
>-4.00 -4.74 -4.67 -- -- -- -- -- -5.07 >-4.30 -4.71 Ovarian
Cancer IGROVI >-4.00 -4.68 -4.57 >-4.30 >-4.30 >-4.30
-4.50 >-4.30- >-4.30 >-4.30 -4.19 OVCAR-3 -- -4.92 -4.45
-8.21 <-8.30 <-8.30 -8.07 -- -4.98 >-4.30 - -4.55 OVCAR-4
-- -4.62 -4.55 -- -- -- -- -- -4.93 >-4.30 -4.19 OVCAR-5
>-4.00 -6.42 -4.33 -6.62 -- <-8.30 -6.95 -6.39 -5.14
>-4.- 30 -4.92 OVCAR-8 >-4.00 -4.69 -4.47 >-4.30
>-4.30 -4.48 >-4.30 >-4.3- 0 >4.30 >-4.30 --
SK-OV-3 -- -4.53 -4.15 >-4.30 -- -4.92 >-4.30 >-4.30
-4.72 >-4- .30 -- Renal Cancer 786-0 >-4.00 -4.83 -4.36
>-4.30 >4.30 -5.08 >-4.30 >-4.30 -- 4.94 >-4.30
>-4.00 A498 >-4.00 -5.00 -4.51 -- -- -- -- -- -5.31
>-4.30 -- ACHN >-4.00 -4.76 <-8.00 -- -4.74 -- -- --
-6.57 -6.61 -4.90 CAKI-1 -- -4.84 -4.54 >-5.99 -- -6.71 -6.91
-6.40 -5.11 -6.30 -4.04 RXF 393 >-4.00 -4.41 -4.53 -6.77 -4.45
-5.99 -7.60 <-8.30 -4.69 >- -4.30 >-4.00 SN12C >-4.00
-4.84 -4.72 -- -- -- -- -- -5.29 -6.02 -4.29 TK-10 >-4.00 -4.81
-4.49 -4.52 -4.60 -5.40 -5.86 -5.22 -5.34 -- -- UO-31 >-4.00
-5.77 -4.68 >-4.30 >-4.30 >-4.30 >-4.30 >-4- .30
-5.10 -4.49 -- Prostate Cancer PC-3 -4.00 -4.89 -4.49 >-4.30
>-4.30 -5.23 -5.75 -4.92 -5.11 >-4.- 30 >-4.00 DU-145 --
-4.72 -4.48 -- -- -- -- -- -5.00 >-4.30 >-4.00 Breast Cancer
MCF7 >-4.00 -4.67 -4.88 >-4.30 >-4.30 -5.13 >-4.30
>-4.30 -- 5.03 >-4.30 -4.05 NCI/ADR-RES -- -6.41 >4.00
>-4.30 >-4.30 -5.09 >-4.30 >-4.3- 0 -5.18 >-4.30
>-4.00 MDA- >-4.00 -4.33 -4.57 -6.35 -- <-8.30 -- --
-6.32 -7.94 -4.84 MB231/ATCC HS 578T >-4.00 >-4.00 -4.08
>-4.30 >-4.30 -4.53 >-4.31 >- -4.30 -5.00 >-4.30 --
MDA-MB-435 -- -4.78 -4.54 >-4.30 >-4.30 -5.17 >-4.30
>-4.30 -4- .94 >-4.30 -- MDA-N >-4.00 -4.90 -- -- -- --
-- -- -- -- -- BT-549 >-4.00 -4.73 -4.81 -7.39 -- -5.54 -5.32
>-4.30 -5.07 >-4.3- 0 -6.32 T-47D >-4.00 -4.73 -4.48
-4.77 -- -- >-4.30 >-4.30 -5.36 >-4.3- 0 -4.05 MG MID --
-4.87 -4.50 -5.04 -4.72 -5.51 -5.12 -4.81 -5.15 -4.66 -- Delta
-4.00 2.31 3.50 3.26 3.58 2.79 3.18 3.49 3.15 3.64 -4.54 Range
0.06 3.18 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 7.20
TABLE-US-00005 TABLE V Log.sub.10LC.sub.50 Panel/Cell Artem-
Trioxane Dimers Pacli- Line isinin 4 5 8a 9 10c 11b 12b 13 14
taxel Leukemia CCRF-CEM -- >-4.00 >-4.00 >-4.30 >-4.30
>-4.30 >-4.30 &g- t;-4.30 >-4.30 >-4.30 >-4.00
HL-60(TB) >-4.00 -4.13 >-4.00 >-4.30 >-4.30 >-4.30
-4.55 &g- t;-4.30 -- >-4.30 >-4.53 K-562 >-4.00
>-4.00 >-4.00 >-4.30 >-4.30 >-4.30 >-4.3- 0
>-4.30 -- >-4.30 >-4.00 MOLT-4 >-4.00 >-4.00
>-4.00 >-4.30 >-4.30 >-4.30 >-4.- 30 >-4.30 --
-- >-4.00 RPMI-8226 >-4.00 >-4.00 >-4.00 >-4.30
>-4.30 >-4.30 -- -- - >-4.30 >-4.30 >-4.00 SR
>-4.00 >-4.00 -- -- -- -- -- -- -- >-4.30 >-4.00
Non-Small Cell Lung Cancer A549/ATCC >-4.00 -4.11 -4.11
>-4.30 >-4.30 >-4.30 >-4.30 &g- t;-4.30 >-4.30
>-4.30 -- EKVX >-4.00 -4.36 -- >-4.30 -- >-4.30
>-4.30 >-4.30 -4.59 &- gt;-4.30 -- HOP-62 >-4.00
-4.20 >-4.00 >-4.30 >-4.30 -4.62 >-4.30 >-- 4.30
-4.54 >-4.30 -4.10 HOP-92 >-4.00 -4.22 -4.05 >-4.30
>-4.30 -4.52 >-4.30 >-4.30- -4.74 >-4.30 -- NCI-H226
>-4.00 >-4.00 -4.11 >-4.30 -- -4.82 -- -- -- -- --
NCI-H23 >-4.00 -4.49 >-4.00 >-4.30 >-4.30 -4.77
>-4.30 >- -4.30 -4.62 >-4.30 -- NCI-H322M -- -4.29 -4.16
>-4.30 >-4.30 -4.57 >-4.30 >-4.30 -4.- 59 >-4.30
>-4.00 NCI-H460 >-4.00 -4.19 >-4.00 >-4.30 >-4.30
-4.62 >-4.30 >- ;-4.30 -4.36 >-4.30 >-4.00
NCI-H-522 -- -4.40 -4.17 >-4.30 >-4.30 >-4.30 >-4.30
<-4.30- >-4.30 >-4.30 >-4.00 Colon Cancer COLO 205
>-4.00 -4.50 -4.15 4.78 -- -5.55 -5.28 >-4.30 >-4.30
>- ;-4.30 >-4.41 HCC-2998 >-4.00 -4.59 >-4.00 -- --
-- -- -- -4.55 >-4.30 -4.26 HCT-116 >-4.00 -4.57 >-4.00
>-4.30 >-4.30 -4.72 >-4.30 >- -4.30 >-4.30
>-4.30 >-4.00 HCT-15 >-4.00 -4.06 -4.03 >-4.30
>-4.30 -4.70 >-4.30 >-4.30- -4.81 >-4.30 >-4.00
HT29 >-4.00 >-4.00 >-4.00 >-4.30 >-4.30 >-4.30
>-4.30- >-4.30 -- -- -4.39 KM12 >-4.00 -4.29 >-4.00
-4.60 -4.36 -5.23 -5.95 -5.02 -4.37 >-4.- 30 >-4.00 SW-620
>-4.00 -4.44 >-4.00 -- -- -- -- -- -4.53 >-4.30 >-4.00
CNS Cancer SF-268 -- -4.23 -4.12 >-4.30 >-4.30 -4.59
>-4.30 <-4.30 -4.31 - >-4.30 -- SF-295 -- -4.39 -4.04 --
-4.60 -- -- -- -4.33 >-4.30 -- SF-539 -4.34 >-4.00 >-4.30
>-4.30 >-4.30 >-4.30 >-4.30 - -4.56 >-4.30
>-4.00 SNB-19 >-4.00 -4.13 >-4.00 >-4.30 -- -4.44
>-4.30 >-4.30 &g- t;-4.30 -- >-4.00 SNB-75 >-4.00
-4.12 >-4.00 >-4.30 >-4.30 -4.32 >-4.30 >-- 4.30 --
-- -- U251 >-4.00 >-4.00 -4.08 >-4.30 >-4.30 -4.72
>-4.30 -- -4.6- 9 >-4.30 -4.15 Melanoma LOX IMVI --
>-4.00 -4.44 -- -- -- -- -- -5.78 -4.39 >-4.15 MALME-3M
>-4.00 -4.28 -4.11 >-4.30 >-4.30 -4.80 >-4.30 >-4.-
30 -4.66 >-4.30 -4.11 M14 >-4.00 -4.14 >-4.00 >-4.30
>-4.30 -4.42 >-4.30 >-4.3- 0 >-4.30 >-4.30 -4.13
SK-MEL2 >-4.00 -4.46 -4.12 >-4.30 >-4.30 >-4.30
>-4.30 >- -4.30 >-4.30 >-4.30 >-4.00 SK-MEL-28
>-4.00 -4.12 >-4.00 >-4.30 >-4.30 >-4.30 >-4.3-
0 >-4.30 -4.34 >-4.30 -- SK-MEL-5 >4.00 -4.53 -4.21 -- --
-- -- -- -4.73 >-4.30 -- UACC-257 >-4.00 -4.30 -4.36
>-4.30 >-4.30 >-4.30 >-4.30 >- ;-4.30 >-4.30
>-4.30 -4.03 UACC-62 >-4.00 -4.29 -4.24 -- -- -- -- -- -4.66
>-4.30 -4.19 Ovarian Cancer IGROVI >-4.00 -4.32 -4.17
>-4.30 >-4.30 >-4.30 >-4.30 >-- 4.30 >-4.30
>-4.30 >-4.00 OVCAR-3 -- -4.42 >-4.00 >-4.30 >-4.30
-5.01 >-4.30 >-4.30 -- 4.51 >-4.30 >-4.00 OVCAR-4 --
-4.16 -4.12 -- -- -- -- -- -4.42 >-4.30 >-4.00 OVCAR-5
>-4.00 -4.54 >-4.00 >-4.30 >-4.30 -4.88 >-4.30
>- -4.30 -4.66 >-4.30 >-4.00 OVCAR-8 >-4.00 -4.03
>-4.00 >-4.30 >-4.30 >-4.30 >-4.30 - >-4.30
>-4.30 >-4.30 >-4.00 SK-OV-3 -- -4.21 >-4.00 >-4.30
-- -4.47 >-4.30 >-4.30 -4.31 &g- t;-4.30 -- Renal Cancer
786-0 >-4.00 -4.31 >-4.00 >-4.30 >-4.30 -4.64
>-4.30 >-4- .30 -4.43 >-4.30 >-4.00 A498 >-4.00
-4.50 -4.21 -- -- -- -- -- -4.74 >-4.30 -4.13 ACHN >-4.00
-4.30 4.47 -- >-4.30 -- -- -- -4.79 >-4.30 -4.45 CAKI-1 --
-4.38 -4.13 >-4.30 >-4.30 -4.93 -4.44 -4.47 -4.66 >-4.3-
0 >-4.00 RXF 393 >-4.00 -4.01 -4.18 >-4.30 >-4.30
-4.73 >-4.30 >-4.3- 0 >-4.30 >-4.30 >-4.00 SN12C
>-4.00 -4.35 -4.26 -- -- -- -- -- -4.72 >-4.30 >-4.00
TK-10 >-4.00 -4.38 -4.06 >-4.30 >-4.30 -4.62 >-4.30
>-4.30 - -4.53 >-4.30 -- UO-31 >-4.00 -5.14 -4.26
>-4.30 >-4.30 >-4.30 >-4.30 >-4- .30 >-4.30
>-4.30 -- Prostate Cancer PC-3 >-4.00 -4.34 >-4.00
>-4.30 >-4.30 -4.62 >-4.30 >-4.- 30 -4.63 >-4.30
>-4.00 DU-145 -- -4.36 -4.13 -- -- -- -- -- -4.6- >-4.30
>-4.00 Breast Cancer MCF7 >-4.00 -4.03 -4.22 >-4.30
>-4.30 >-4.30 >-4.30 >-4.- 30 -4.44 >-4.30
>-4.00 NCI/ADR-RES -- -4.52 >-4.00 >-4.30 >-4.30 -4.63
>-4.30 >-4.- 30 -4.65 >-4.30 >-4.00 MDA- >-4.00
>-4.00 -4.15 >-4.30 -- -5.02 -- -- -4.77 >-4.30 -4- .29
MB231/ATCC HS 578T >-4.00 >-4.00 >-4.00 >-4.30
>-4.30 >-4.30 >-4- .30 >-4.30 -4.35 >-4.30 --
MDA-MB-435 -- -4.30 -4.09 >-4.30 >-4.30 -4.60 >-4.30
>-4.30 -4- .46 >-4.30 -- MDA-N >-4.00 -4.45 -- -- -- --
-- -- -- -- -- BT-549 >-4.00 -4.31 -4.30 >-4.30 -- -4.61
>-4.30 >-4.30 -4.61 - >-4.30 >-4.00 T-47D >-4.00
-4.17 >-4.00 >-4.30 -- >-4.30 >-4.30 >-4.30-
>-4.30 >-4.30 >-4.00 MG MID -- -4.26 -4.09 -4.32 -4.31
-4.55 -4.37 -4.32 -4.51 -4.30 -- Delta -4.00 0.88 0.37 0.46 0.29
1.00 1.58 0.70 1.27 0.08 -4.06 Range 0.00 1.14 0.47 0.48 0.30 1.25
1.65 0.72 1.49 0.09 .045
The data indicate that alcohol and diol dimers 4 and 5 are
selectively and strongly inhibitory to leukemia cell line RPM
1-8226, to melanoma cell line SK-MEL-5, and to renal cancer cell
line ACHN. The epoxide dimer 6 and the ketone dimer 7 are less
inhibitory. The data further indicate that the carboxylic acid
derivatives 8a, 9, 10c, 11b, and 12b are also selectively and
strong inhibitory to colon cancer KM12, ovarian cancer OVCAR 3,
and to breast cancer MDA-MB-435. The data lastly indicate that the
acetic acid derivative 12b is highly selective and especially
inhibitory.
The dimers 4, 5, 8a, 9, 10c, 11b and 12b of the present invention
in most instances are as potent and in some instances more potent
than paclitaxel. The data in Tables III, IV and V are graphically
represented in FIGS. 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j and 7k
through FIGS. 15j. Dose response curves, shown in the above
mentioned Figures, are obtained by exposing various cancer cell
lines to compounds having a known concentration ([log.sub.10M]),
as discussed in detail above, and then plotting the percentage
growth of each cell line for each concentration. The drug
concentration limits that are tested are between 10.sup.-4 or
-4.00M and 10.sup.-9 or -9.00M. The -4.00M value being the high
concentration and the -9.00M value being the low concentration.
Percentage growth is determined by dividing the number or mass of
cells in the test well by the number or mass of cells in a control
well. Referring to the leukemia cell line MOLT-4 in FIGS. 7a, 7b,
7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j and 7k the first comparison that is
made between artemisinin, paclitaxel, and the dimers 4, 5, 8a, 9,
10c, 11b, and 12b of the present invention are the drug
concentrations which are necessary to inhibit growth, graphically
represented in FIGS. 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j and 7k
as the concentration necessary to achieve the percentage growth
value of +50. As discussed previously, the five drug dilutions
routinely tested range from 10.sup.-4 to 10.sup.-9 molar.
Therefore, concentrations less than or greater than 10.sup.-9 and
10.sup.-4 molar, respectively, that are required to achieve a
desired result are not determined. Referring now to FIG. 7a, some
concentration of paclitaxel that is less than 10.sup.-8M is
necessary to achieve primary growth inhibition; in fact the lower
concentrations have been determined for this drug and the
concentration at which primary growth inhibition occurs using
paclitaxel is at 10.sup.-11 molar. FIG. 7b indicates that some
concentration of artemisinin that is greater than 10.sup.-4 molar
is necessary to achieve primary growth inhibition. Referring to
the alcohol and diol trioxane dimers 4 and 5, dose response curves
in FIGS. 7c and 7d, respectively, the leukemia cell line MOLT-4
displays primary growth inhibition at drug concentrations that are
less than 10.sup.-7 and less than 10.sup.-8 molar, respectively.
Referring to the carboxylic acid derivatives 8a, 9, 10c, 11b and
12b, dose response curves in FIGS. 7e, 7f, 7g, 7h and 7i,
respectively, the leukemia cell line MOLT-4 displays primary
growth inhibition at drug concentrations that are less than
10.sup.-8, 10.sup.-5, 10.sup.-8 and 10.sup.-7 molar respectively.
The drug concentration at which artemisinin is considered
cytostatic, i.e., percentage growth is equal to 0, is at a
concentration greater than 10.sup.-4 molar. The dimers 4, 5, 8a,
9, 10c, 11b, and 12b reach cytostasis at some concentration
greater than 10.sup.-4 M, while the paclitaxel concentration
necessary to achieve cytostasis is also some value greater than
10.sup.-4 M. Cytotoxicity, i.e., the concentration for which the
percentage growth is equal to -50, occurs at a concentration
greater than 10.sup.-4 M for paclitaxel, artemisinin, for both
alcohol and diol trioxane dimers 4 and 5, and for carboxylic acid
dimers 8a, 9, 10c, 11 and 12b, respectively.
The potency of the dimers 4, 5, 8a, 9, 10c, 11b, and 12b,
respectively, of the present invention as compared to artemisinin
and paclitaxel varies from cell line to cell line. The mean values
for each drug are presented at the end Tables III, IV and V and
the dimers 4, 5, 8a, 9, 10c, 11b, and 12b of the present invention
are more potent than artemisinin and equivalent to and in many
instances higher in potency than paclitaxel.
The dihydroartemisinin dimer disclosed by M. Cao, et al., and
tested by D. L. Klayman and H. J. Woerdenbag, discussed
previously, was approximately twenty-two times more potent at
causing 50% growth inhibition in one cancer cell line than
artemisinin. With respect to the drug concentrations causing 50%
growth inhibition, the dimers 4, 5, 8a, 9, 10c, 11b, and 12b were
at least 100 times more potent than artemisinin. When interpreting
the mean values, it is important to take into consideration that
drug concentrations less than 10.sup.-9M and greater then 10M were
not collected, and this factor is reflected in the range.
For a further comparison on the effects of the trioxane dimers of
the present invention on various cancer cell lines versus the
effects of artemisinin and paclitaxel on the same cell lines see
FIGS. 8a, b, c, d, e, f, g, h, i, j and k for non-small cell lung
cancer cell lines, FIGS. 9a, b, c, d, e, f, g, h, i, j and k for
colon cancer cell lines, FIGS. 10a, b, c, d, e, f, g, h, l, j and
k for CNS cancer cell lines, FIGS. 11a, b, c, d, e, f, g, h, i, j
and k for melanoma cancer cell lines, FIGS. 12a, b, c, d, e, f, g,
h, i, j and k for ovarian cancer cell lines, FIGS. 13a, b, c, d,
e, f, g, h, i, j and k for renal cancer cell lines, FIGS. 14a, b,
c, d, e, f, g, h, i, and j for prostate cancer cell lines and
FIGS. 15a, b, c, d, e, f, g, h, i, and j for breast cancer cell
lines.
Acute Toxicity Study of Three
Anti-Malarial Compounds in Male CD-1 Mice
The purpose of this study was to determine the relative toxicity
of four structurally similar anti-malarial compounds (13, 16, 19,
and sodium artesunate) following a single intraperitoneal (ip)
injection. This study was not performed in compliance with the
U.S. FDA "Good Laboratory Practice for Nonclinical Laboratory
Studies" (GLP) as described in 21 CFR Part 58; however,
documentation of all procedures and quality control checking of
data was performed as for GLP studies.
Materials and Methods
A. Test Article and Dose
Preparation
Compounds 13, 16, 19 and sodium artesunate (Mepha Ltd., Lot No.
1), were provided by NIAID via McKesson BioServices HBOC
(Rockville, Md.). Each compound was dissolved in DMSO (Mallinkrodt
Lot No. V18H15) to achieve a concentration of 200 mg/ml, and then
3 parts sesame oil (Spectrum Lot No. M10656) was added to make a
working concentration of 50 mg/ml for dose administration.
Stability, strength, and uniformity of the test articles in the
dose formulations were not determined for this study.
B. Test System
Forty-two CD1 male mice purchased from Charles River Laboratories
(Wilmington, Mass.) were used in the study. Mice were quarantined
for 3 days prior to initiation of the study. General procedures
for animal care and housing were in accordance with the National
Research Council (NRC) Guide for the Care and Use of Laboratory
Animals (1996) and the animal welfare standards incorporated in 9
CFR Part 3, 1991. Mice were approximately 6 weeks old and weighed
25.2-31.2 g at study initiation. They were individually housed
under a 12 hr light-dark cycle, with a temperature range of
68-72.degree. F. and 33-67% humidity. Purina Certified Rodent Chow
#5002 and purified tap water were available ad libitum.
C. Experimental Design and Data
Collection
Mice were weighed and randomized into treatment groups on the day
prior to the first dose administration. Due to limitations in the
amount of available test materials, fewer mice in 1000 mg/kg
groups were treated than specified in the protocol. The numbers of
animals intended to be used and actually used with each compound
at each dose level are shown in the table below; the only
differences are in the high-dose groups.
Mice were administered either compounds 13, 16,19 or sodium
artesunate once ip at does levels at 125, 250, 500, or 1000 mg/kg.
Control animals were administered a vehicle solution (25% DMSO and
75% sesame oil) at a volume of 20 ml/kg. Surviving animals were
sacrificed on Day 8 and blood was collected for clinical pathology
evaluations.
Clinical signs were observed daily, including evaluation of the
injection site 1 to 2 hr. after treatment on Day 1 and once daily
on Days 2-8. Mortality and morbidity were checked twice daily on
weekdays and once daily on the weekend, see Table VI. Animals were
weighed daily and prior to necropsy.
TABLE-US-00006 TABLE VI Mortality Data 750 mg/kg 500 mg/kg 250
mg/kg 125 mg/kg Control No death (12.5 and 18.75 ml/kg) Na
Artesunate -- 3/3 dead 1/3 dead No death 13 2/3 dead 3/3 dead No
death No death 16 3/3 dead 3/3 dead No death No death 19 3/3 dead
1/3 dead No death No death
TABLE-US-00007 TABLE VII Efficacy Study Blood Schizontocidal
Activity Route: IV Route: PO Compound ED.sub.50 ED.sub.90
ED.sub.50 ED.sub.90 Na Artesunate 5.0 40.0 6.0 60.0 (2.9-7.5)
(23.0-60.0) (4.0-10.0) (40.0-100.0) 13 0.55 2.0 4.0 9.0 (0.1-0.8)
(0.8-3.2) (2.0-7.0) (4.3-17.0) 16 60.0 1000.0 12b 5.2 10.0 6.0
19.0 (4.9-6.0) (6.9-15.0) (2.7-13.0) (8.0-39.0) 19 1.7 4.5 5.5
18.0 (1.1-4.9) (3.0-11.0) (2.9-13.0) (8.0-38.0)
In conclusion, new C-10 non-acetal trioxane dimer 3, easily
prepared on gram scale and thermally stable, can be used to make a
diverse series of 3-carbon atom linked, oxygenated dimers 4-7
without destroying the critical pharmacophore peroxide bond. Each
of the new trioxane dimers 4, 5, and 7 is 10 times more
antimalarially potent in vitro than the natural trioxane
artemisinin (I), and alcohol and diol dimers 4 and 5 are strongly
inhibitory but not cytotoxic toward several human cancer cell
lines. Moreover, water-soluble trioxane dimers 8a-10c and 12b are
orally active new antimalarials that are more efficacious than
artelinic acid and than sodium artesunate in mice. These
semi-synthetic new chemical entities 4 and 5 and especially 8a-10c
and 12b, therefore, deserve further preclinical evaluation as
potential drug candidates for chemotherapy of malaria and cancer.
Dimers 13 and 19 are more efficacious (when administered both
orally and i.v.) and less toxic (when administered
intraperitoneally to mice as a single dose) than clinically-used
sodium artesunate, thereby giving them a better antimalarial
therapeutic index than sodium artesunate.
The invention is further illustrated by the following non-limited
examples. All scientific and technical terms have the meanings as
understood by one with ordinary skill in the art. The specific
examples which follow illustrate the synthesis of representative
compounds of the instant invention and are not to be construed as
limiting the invention in sphere or scope. The methods may be
adapted to variation in order to produce compounds embraced by
this invention but not specifically disclosed. Further, variations
of the methods to produce the same compounds in somewhat different
fashion will be evident to one skilled in the art. The synthetic
descriptions and specific examples that follow are only intended
for the purposes of illustration, and are not to be construed as
limiting in any manner to make compounds of the present invention
by other methods.
EXAMPLES
Unless otherwise noted, reactions were run in oven-dried glassware
under an atmosphere of argon. Diethyl ether (ether) and
tetrahydrofuran (THF) were distilled from sodium benzophenone
ketyl prior to use. Methylene chloride (CH.sub.2Cl.sub.2) was
distilled from calcium hydride prior to use. All other compounds
were purchased from Aldrich Chemical Company and used without
further purification. Analytical thin-layer chromatography (TLC)
was conducted with Silica Gel 60 F254 plates (250 micrometer
thickness, Merck). Column chromatography was performed using flash
silica gel (particle size 400-230 mesh). Yields are not optimized.
Purity of final products was judged to be >95% based on their
chromatographic homogeneity. High performance liquid
chromatography (HPLC) was carried out with a Rainin HPLX system
equipped with two 25 mL/min preparative pump heads using a Rainin
Dynamax 10 mm.times.250 mm (semi-preparative) column packed with
60 .ANG. silica gel (8 .mu.m pore size) as bare silica. Melting
points were measured using a Mel-Temp metal-block apparatus and
are uncorrected. Nuclear magnetic resonance (NMR) spectra were
obtained on a Varian XL-400 spectrometer, operating at 400 MHz for
.sup.1H, 162 MHz for .sup.31P 100 MHz for .sup.13C. .sup.1H and
.sup.13C chemical shifts are reported in parts per million (ppm)
downfield from tetramethylsilane, .sup.31P chemical shifts are
measured using 85% phosphoric acid as an external reference.
Splitting patterns are described as singlet(s), doublet(d),
triplet(t), quartet(q), quintet (qt), sextet (st), multiplet (m)
and broad (br). Infrared (IR) spectra were obtained using a
Perkin-Elmer 1600 FT-IR spectrometer. Resonances are reported in
wavenumbers (cm.sup.-1). Low and high resolution mass spectra
(LRMS and HRMS) were obtained with electronic or chemical
ionization (El or Cl) either (1) at Johns Hopkins University on a
VG Instruments 70-S Spectrometer run at 70 eV for El and run with
ammonia (NH.sub.3), butane (C4H.sub.10) or methane (CH.sub.4) as
carrier gas for Cl or (2) at Ohio State University with a 3-Tesla
Finnigan FTMS-2000 Fourier Transform mass spectrometer. Samples
were sprayed from a commercial Analytica electrospray ionization
source, and then focused into the FTMS cell using a home-built set
of ion optics. For ESI analysis, most compounds were sprayed from
a micromolar concentration of the analyte in various solvent
mixtures, such as tetrahydrofuran/CH.sub.3OH, with added NaCl.
This process generated the sodiated molecular ion (usually as the
singly-charged species), denoted as (M+Na).sup.+. But in some
cases, acetic acid or trifluoroacetic acid was used to generate
the protonated molecular ion (M+H)+ instead. Electron impact (El)
ionization was performed with a Kratos MS-25, using 70 eV
ionization conditions. Combustion analyses were conducted by
Atlantic Microlab (Norcross, Ga.). Various methods of purifying
the products of the present invention are known and understood by
those skilled in the art and the purification methods presented in
the Examples is solely listed by way of example and is not
intended to limit the invention.
Example 1
Synthesis of bis-trioxane O-allyl
ether 12a and bis-trioxane O-acetic acid 12b
Synthesis of bis-trioxane O-allyl
ether 12a.
To a solution of bis-trioxane primary alcohol 4 (200 mg, 0.33
mmol) in anhydrous tetrahydrofuran (20 mL) at -78.degree. C. was
added KHMDS (0.5 M sol. in toluene, 2 mL, 1 mmol) in a dropwise
manner. The reaction was stirred at -78.degree. C. for 30 mins, at
which time allyl bromide (0.4 mL, I mmol) and 18-crown-6
(catalytic) were added. The reaction was then stirred at
-78.degree. C. for a further 1 hour, at which time TLC analysis
showed complete consumption of starting material. The reaction was
quenched with water (5 mL) and organics were extracted with
methylene chloride (3.times.20 mL), dried (MgSO.sub.4) and
concentrated in vacuo. Column chromatography on silica eluting
with 10-12% ethyl acetate/hexanes isolated bis-trioxane O-allyl
ether 12a as a viscous oil (204 mg, 96%). .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 5.98-5.88 (m, 1H), 5.32 (s, 2H), 5.28-5.23 (m,
1H), 5.14-5.10 (m, 1H), 4.34-4.28 (m, 1H), 4.24-4.17 (m, 1H),
4.04-3.90 (m, 2H), 3.61-3.54 (m, 2H), 2.76-2.60 (m, 2H), 2.38-3.26
(m, 2H), 2.10-1.20 (m), 0.99-0.81 (m, 14H); .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 135.4, 116.1, 103.1, 102.9, 88.9, 88.4, 81.1,
74.7, 72.7, 71.7, 71.5, 52.4, 52.2, 44.6, 44.4, 37.3, 36.5, 35.6,
34.5, 34.4, 30.5, 30.4, 29.9, 29.6, 26.1, 26.0, 24.9, 24.6, 24.5,
20.2, 20.1, 13.3, 13.0.
Synthesis of bis-trioxane
O-acetic acid 12.
To a solution of bis-trioxane O-allyl ether 12a (115 mg, 0.178
mmol) in ethyl acetate (3.0 mL), acetonitrile (3.0 mL) and water
(1.0 mL) was added ruthenium (III) chloride hydrate (7.4 mg, 0.036
mmol) and sodium periodate (266 mg, 1.25 mmol) (on addition of
ruthenium chloride the solution turned black). The reaction was
stirred at room temperature for 30 mins (the color of the solution
turned to pale orange) before the reaction mixture was poured into
a mixture of ethyl acetate (30 mL) and saturated aqueous
NH.sub.4Cl solution (20 mL). Organics were extracted with ethyl
acetate (2.times.30 mL), filtered through a pad of celite, dried
(MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography (1% acetic acid in 40% ethyl acetate/hexane)
isolated bis-trioxane O-acetic acid 12b as a white solid (52.0 mg,
0.078 mmol, 44%). Mp=86-90.degree. C.; .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 5.33 (s, 2H), 4.46-4.39 (m, 1H), 4.38-4.33 (m,
1H), 4.15 (d, 1H, J=16.4), 4.03 (d, 1H, J=16.4), 3.86 (dd, 1H,
J=8.8, J=5.2), 3.57 (dd, 1H, J=8.8, J =4.4), 2.71-2.52 (m, 2H),
2.37-2.29 (m, 2H), 2.08-1.18 (m, 30H, including two singlets at
1.39 and 1.38), 0.98-0.85 (m, 2H), 0.94 (apparent doublet, 6H,
J=6.0), 0.86 (d, 3H, J=7.2), 0.85 (d, 3H, J=7.2); .sup.13C NMR
(100 MHz, CDCl.sub.3) .delta. 171.7, 103.4, 103.1, 89.4, 89.2,
81.1, 81.0, 74.3, 73.6, 71.5, 69.1, 52.2, 52.1, 44.3, 44.1, 37.5,
36.5, 36.0, 34.4, 30.7, 30.7, 30.6, 26.0, 25.9, 24.8, 24.7, 20.2,
20.1,12.9, 12.8; IR (film, cm.sup.-1) 3506 (br), 2939, 2875, 1759,
1739, 1451, 1377, 1279, 1251, 1206, 1187, 1125, 1052, 1011, 929,
910, 826, 731; HRMS(ES) m/z calcd for C.sub.36H.sub.56O.sub.11Na
(M+Na) 687.3715, found 687.3695.
Example 2
Synthesis of
.alpha.-dihydroartemisinin acetate 2
To a solution of artemisinin 1 (565 mg, 2.00 mmol) in anhydrous
methylene chloride (15.0 mL) at -78.degree. C. was added DIBAL
(1.0 M in toluene, 2.4 mL, 2.4 mmol) in a dropwise manner. The
reaction was stirred at -78.degree. C. for one hour, at which time
TLC analysis confirmed complete consumption of starting material.
Pyridine (0.50 mL, 6.18 mmol), 4-(dimethylamino)-pyridine (292 mg,
2.4 mmol) and finally acetic anhydride (0.760 mL, 8.05 mmol) were
addded and the reaction was stirred vigorously at -78.degree. C.
for 3 hours before being allowed to warm to room temperature and
stir overnight. The reaction was then quenched with saturated
NH.sub.4Cl solution (20 mL) and organics were extracted with
methylene chloride (3.times.20 mL), washed with brine, dried
(MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 14% ethyl acetate/hexanes
isolated .alpha.-dihydroartemisinin acetate 2 as a white solid
(600 mg, 1.84 mmol, 92%) with the following characteristic peaks:
.sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 5.78 (d, 1H, J=9.6),
5.44 (s, 1H), 2.60-2.51 (m, 1H), 2.41-2.33 (m, 1H), 2.12 (s, 3H),
1.43 (s, 3H), 0.96 (d, 3H, J=6.0), 0.84 (d, 3H, J=7.2).
Example 3
Synthesis of trioxane isobutene
dimer 3
A solution of dihydroartemisinin acetate 2 (DHA acetate) (872 mg,
2.67 mmol) and the allylic bis-silane linker (267 mg, 1.34 mmol)
in methylene chloride (50 mL) was cooled to -78.degree. C. Tin
tetrachloride (1M solution in CH.sub.2Cl.sub.2, 2.67 ml, 2.67
mmol) was further diluted with CH.sub.2Cl.sub.2 (3 mL) and was
added to the reaction mixture dropwise using a syringe pump at the
rate of 6 ml/hour. The reaction was stirred at -78.degree. C. for
a further 45 minutes at which time TLC analysis confirmed complete
consumption of starting material. Saturated ammonium chloride
solution (10 mL) was then added and the reaction was allowed to
warm to room temperature naturally. Organics were extracted with
methylene chloride (3.times.20 mL), dried (Na.sub.2SO.sub.4) and
concentrated in vacuo. Gradient column chromatography on silica
eluting with 5%, 7%, 8% and finally 10% ethyl acetate/hexanes
isolated trioxane isobutene dimer 3 as a white solid (564 mg, 0.96
mmol, 71%). Mp=132-133.degree. C.; .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 5.41 (s, 2H), 4.87 (s, 2H), 4.30 (ddd, 2H,
J=10.4, J=5.6, J=4.0), 2.75-2.67 (m, 2H), 2.61-2.54 (m, 2H),
2.37-2.23 (m, 4H), 2.04-1.98 (m, 2H), 1.91-1.84 (m, 2H), 1.81-1.75
(m, 2H), 1.67-1.56 (m, 4H), 1.52-1.32 (m, 6H), 1.39 (s, 6H),
1.23-1.20 (m, 2H), 0.94 (d, 6H, J=6.0), 0.90 (d, 6H, J=7.6),
0.98-0.86 (m, 2H); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.
147.4, 113.1, 103.1, 88.6, 81.2, 75.5, 52.4, 44.5, 37.1, 36.7,
35.2, 34.5, 30.6, 26.2, 24.7, 24.6, 20.2, 13.3; IR (film,
cm.sup.-1) 3060, 2938, 2875, 1641, 1451, 1375, 1121, 1092, 1054,
1007, 878, 732; HRMS(ES) m/z calcd for C.sub.34H.sub.52O.sub.8Na
(M+Na) 611.3560, found 611.3555; Anal (C.sub.34H.sub.52O.sub.8) C,
H.
Example 4
Synthesis of bis-trioxane primary
alcohol 4
A solution of trioxane isobutene dimer 3 (0.89 g, 1.51 mmol) in
anhydrous tetrahydrofuran (25 mL) was cooled to 0.degree. C.
Borane-dimethyl sulfide complex (BH.sub.3DMS) (2.0 M solution in
diethyl ether, 0.9 mL, 1.80 mmol) was carefully added and the
reaction was allowed to warm to room temperature and stir for 3
hours. At this time TLC analysis confirmed that no starting
material remained. A suspension of sodium perborate4H.sub.2O
(NaBO.sub.34H.sub.2O) (1.17 g, 7.60 mmol) in water (12 mL) was
slowly added and the resulting suspension was allowed to stir for
17 hours. Water (10 mL) and methylene chloride (50 mL) were added
and organics were extracted with methylene chloride (3.times.20
mL), dried (Na.sub.2SO.sub.4) and concentrated in vacuo to give a
white solid. Gradient column chromatography on silica eluting with
20%, 30% and finally 40% ethyl acetate/petroleum ether isolated
bis-trioxane primary alcohol 4 as a white solid (0.85 g, 1.40
mmol, 93%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 6 35 (s,
1H), 5.34 (s, 1H), 4.47-4.40 (m, 1H), 4.33 (qt, 1H, J=6.0),
3.83-3.75 (m, 1H), 3.67-3.60 (m, 1H), 3.17 (dd, 1H, J=7.6, J=6.1),
2.64 (qt, 1H, J=6.9), 2.59 (qt, 1H, J=6.9), 2.32 (t, br, 2H,
J=14.1), 2.06-1.97 (m, 3H), 1.95-1.87 (m, 2H), 1.86-1.74 (m, 2H),
1.70-1.55 (m, 8H), 1.50-1.30 (m, 14H, including singlet at 1.40),
0.99-0.90 (m, 2H), 0.95 (d, 6H, J=5.8), 0.87 (apparent t, 6H,
J=6.9); .sup.13C NMR (CDCl.sub.3, 100 MHz) .delta. 103.12, 102.97,
89.47, 89.22, 81.11 (2), 73.86, 71.27, 65.12, 52.20, 52.07, 44.18,
44.01, 37.68, 37.46, 37.43, 36.52, 36.51, 34.40, 34.37, 31.26,
30.74 (2), 30.65, 25.95, 25.89, 24.83 (2), 24.73, 24.70, 20.15,
20.10, 12.89, 12.61; HRMS (El, m/z) for C.sub.34H.sub.54O.sub.9Na
requires 629.3660, found 629.3697; IR (film, cm.sup.-1) 3490; Mp.
81-82.degree. C.; Anal (C.sub.34H.sub.56O.sub.10) C, H.
Example 5
Synthesis of bis-trioxane vicinal diol 5
To a solution of trioxane isobutene dimer 3 (21.0 mg, 0.036 mmol)
and 4-methylmorpholine N-oxide (5.0 mg, 0.043 mmol) in acetone
(2.0 mL) was added osmium tetroxide (25 mg/2 mL aqueous solution,
0.016 mL, catalytic) and the reaction was stirred vigorously at
room temperature for 24 hrs. The reaction mixture was then
quenched with saturated aqueous NaHSO.sub.3 solution (2.0 mL) and
stirred for an additional 30 mins (during which time the reaction
turned a pale orange color). The reaction mixture was poured into
a mixture of diethyl ether (20 mL) and saturated aqueous
NH.sub.4Cl solution (20 mL) and organics were extracted with ethyl
acetate (2.times.30 mL), washed with brine, dried (MgSO.sub.4) and
concentrated in vacuo. Flash column chromatography on silica
eluting with 50% ethyl acetate/hexanes) isolated bis-trioxane
vicinal diol 5 as a white solid (20.3 mg, 0.033 mmol, 92%).
Mp=159-160.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.36 (s, 1H), 5.35 (s, 1H), 4.74-4.70 (m, 1H), 4.56-4.51 (m, 1H),
4.09 (s, 1H), 3.71-3.62 (m, 2H), 3.12 (t, 1H, J=7.2), 2.64-2.52
(m, 2H), 2.36-2.26 (m, 2H), 2.04-1.99 (m, 2H), 1.96-1.63 (m, 12H),
1.46-1.20 (m, 14H, including two singlets at 1.40 and 1.39), 0.96
(d, 3H, J=6.0), 0.95 (d, 3H, J=6.0), 0.89 (d, 3H, J=7.6), 0.88 (d,
3H, J=7.6), 0.98-0.86 (m, 2H); .sup.13C NMR (100 MHz, CDCl.sub.3)
.delta. 103.0, 102.9, 89.7, 89.5, 81.1, 81.0, 74.7, 70.6, 70.5,
68.4, 52.0, 43.8, 43.7, 37.8, 37.5, 36.5, 34.9, 34.3, 31.0, 30.9,
25.9, 25.9, 24.9, 24.8, 24.8, 20.1, 12.5, 12.4; IR (film,
cm.sup.-1) 3499, 2951, 2876, 1453, 1378, 1207, 1108, 1054, 1009,
912, 878, 844, 732; HRMS(ES) m/z calcd for
C.sub.34H.sub.54O.sub.10Na (M+Na) 645.3609, found 645.3559.
Example 6
Synthesis of bis-trioxane epoxide
6
To a solution of trioxane isobutene dimer 3 (34.1 mg, 0.058 mmol)
in anhydrous methylene chloride (10.0 mL) at -78.degree. C. was
rapidly added dimethyl dioxirane (DMDO) (0.08 M solution in
acetone, 3.8 mL, 0.29 mmol). The reaction was stirred at
-78.degree. C. for 30 minutes before being allowed to warm to room
temperature. The reaction was then concentrated in vacuo, giving a
yellow oil. Flash column chromatography on silica eluting with 20%
theyl acetate/hexanes isolated bis-trioxane epoxide 6 as a white
solid (28.1 mg, 0.047 mmol, 80%). Mp=147-148.degree. C.; .sup.1H
NMR (400 MHz, CDCl.sub.3) .delta. 5.48 (s, H), 5.43 (s, H), 4.45
(dd, 1H, J=10.0, J=6.0), 4.22 (dd, 1H, J=10.0, J=6.0), 2.82-2.72
(m, 2H), 2.68-2.62 (m, 3H), 2.43-2.33 (m, 3H), 2.02-1.97 (m, 2H),
1.88-1.82 (m, 2H), 1.75-1.70 (m, 2H), 1.62-1.58 (m, 2H), 1.54-1.26
(m, 11H), 1.39 (s, 6H), 0.98-0.88 (m, 3H), 0.93 (d, 6H, J=6.4),
0.92 (d, 6H, J=6.4), 0.80 (d, 6H, J=7.6); .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 103.43, 103.40, 87.94, 87.93, 81.10, 81.07,
75.44, 74.37, 60.43, 54.46, 52.54, 52.50, 44.58, 36.91, 36.70,
34.40, 33.50, 33.01, 30.40, 30.36, 26.18, 24.45, 24.35, 24.32,
20.22, 20.19, 13.69, 13.51; IR (film, cm.sup.-1) 2939, 2875, 1452,
1376, 1280, 1208, 1188, 1123, 1091, 1057, 1006, 941, 878, 754;
HRMS(ES) m/z calcd for C.sub.34H.sub.52O.sub.9Na (M+Na) 627.3509,
found 627.3478.
Example 7
Synthesis of bis-trioxane ketone
7
To a solution of trioxane isobutene dimer 3 (30 mg, 0.051 mmol) in
anhydrous N,N-dimethylformamide (25 .mu.L) was added OSO.sub.4
(2.5% weight % in t-BuOH, 0.1 mol %). The reaction mixture was
stirred for 5 minutes before Oxone.RTM. (63 mg, 0.2 mmol) was
added in one portion. The reaction was then stirred for a further
2 hours, at which time TLC analysis confirmed full consumption of
starting material. The reaction was quenched with saturated
Na.sub.2SO.sub.3 solution (10 mL) and water (10 mL) and stirred
for 1 hour before organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo. Flash column chromatography on silica eluting with 25%
ethyl acetate/hexanes) isolated bis-trioxane ketone 7 as a white
solid (21 mg, 0.035 mmol, 70%). Mp=120-121.degree. C.; .sup.1H NMR
(400 MHz, CDCl.sub.3) .delta. 5.34 (s, 2H), 4.75 (m, 2H), 2.90 (m,
2H), 2.75 (m, 2H), 2.59 (dd, 2H, J=16, J=4), 2.33 (dt, 2H, J=16,
J=9), 2.04-1.96 (m, 2H), 1.94 (m, 2H), 1.79 (m, 2H), 1.68-1.57 (m,
6H), 1.48-1.22 (m, 14H), 0.99 (d, 6H, J=6.4), 0.88 (d, 6H, J=7.2);
.sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 196.8, 103.8, 89.3,
71.6, 52.5, 44.5, 44.3, 37.7, 36.8, 34.7, 30.3, 26.3, 25.0, 24.8,
20.4, 13.8; IR (film, cm.sup.-1) 1722; HRMS(ES) m/z calcd for
C.sub.33H.sub.50O.sub.9Na (M+Na) 613.3347, found 613.3303.
Example 8
Synthesis of bis-trioxane primary
succinate monoester 8a
To a solution of bis-trioxane primary alcohol 4 (50 mg, 0.082
mmol) and succinic anhydride (24 mg, 0.24 mmol) in methylene
chloride (10 mL) at 0.degree. C. was added
4-(dimethylamino)-pyridine (10 mg, 0.082 mmol). The reaction was
allowed to warm to room temperature and was then stirred for 12
hours, at which TLC analysis showed complete consumption of
starting material. Organics were extracted with ethyl acetate
(3.times.30 mL), washed with brine (10 mL), dried (MgSO.sub.4) and
concentrated in vacuo. Flash column chromatography on silica
eluting with 50% ethyl acetate/hexanes to isolated bis-trioxane
primary succinate monoester 8a as a white solid (40 mg, 0.068
mmol, 84%). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 5.39 (s,
1H), 5.31 (s, 1H), 4.39-4.32 (m, 2H), 4.28-4.18 (m, 3H), 2.74-2.54
(m, 6H), 2.38-2.24 (m, 2H), 2.22-2.12 (m, 1H), 2.06-1.96 (m, 2H),
1.95-1.85 (m, 2H), 1.84-1.60 (m, 11H), 1.48-1.20 (m, 16H),
1.00-0.80 (m, 12H); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.
175.4, 172.0, 102.9, 103.6, 89.4, 88.5, 81.1, 74.1, 71.1, 67.1,
52.4, 52.1, 44.6, 44.1, 37.4, 37.3, 36.6, 36.5, 34.4, 34.3, 30.5,
30.4, 30.0, 29.7, 29.4, 29.0, 26.0, 25.9, 24.7, 20.3, 20.1, 13.3,
12.7; HRMS(ES) m/z calcd for C.sub.38H.sub.58O.sub.12Na (M+Na)
729.3820, found 729.3795.
Example 9
Synthesis of bis-trioxane primary
alcohol isonicotinate 8b
To a stirring suspension of bis-trioxane primary alcohol 4 (30.4
mg, 0.050 mmol) and isonicotinic acid (20.1 mg, 0.163 mmol) in
anhydrous methylene chloride (1 mL) was added
4-(dimethylamino)-pyridine (23.5 mg, 0.192 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide (EDC)
hydrochloride (39.2 mg, 0.204 mmol). A further 1.5 mL of anhydrous
methylene chloride was added to wash down the flask walls and the
reaction was stirred at room temperature for 3 hours, at which
time TLC analysis showed full consumption of starting material.
Water (5 mL), saturated NaHCO.sub.3 solution (5 mL) and methylene
chloride (5 mL) were added and organics were extracted with
methylene chloride (3.times.20 mL), dried (Na.sub.2SO.sub.4) and
concentrated in vacuo to give a white solid. Gradient column
chromatography on silica (crude was dry-loaded) eluting firstly
with 25% ethyl acetate/petroleum ether and then 30% ethyl
acetate/petroleum ether isolated bis-trioxane primary alcohol
isonicotinate 8b as a white solid (32.6 mg, 0.046 mmol, 91%).
Mp=74-78.degree. C.; [.alpha.].sub.D.sup.24.5 77.8 (CHCl.sub.3,
c=0.06); .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.78 (s, br,
2H), 7.86 (s, br, 2H), 5.33 (s, 1H), 5.29 (s, 1H), 4.55 (s, 1H),
4.54 (s, 1H), 4.51-4.44 (m, 1H), 4.37-4.30 (m, 1H), 2.70 (st, 1H,
J=7.0), 2.59 (st, 1H, J=7.0), 2.45-2.36 (m, br, 1H), 2.31 (td, 2H,
J=14.0, J=3.7), 2.05-1.96 (m, 2H), 1.95-1.73 (m, 6H), 1.69-1.50
(m, 6H), 1.41-1.15 (m, 14H, including two singlets at 1.40 and
1.39), 0.98-0.92 (m, 2H), 0.96 (d, 3H, J=5.9), 0.94 (d, 3H,
J=5.9), 0.88 (d, 3H, J=7.4), 0.87 (d, 3H, J=7.4); .sup.13C NMR
(100 MHz, CDCl.sub.3) .delta. 164.99, 150.49 (2), 137.93, 122.91
(2), 103.16, 102.87, 89.52, 88.83, 81.12, 81.11, 73.23, 70.83,
68.10, 52.30, 52.07, 44.32, 44.06, 37.50, 37.47, 36.64, 36.54,
34.42, 34.39, 33.95, 30.61, 30.58, 30.49, 30.15, 26.02, 26.01,
24.97, 24.89, 24.76, 24.67, 20.17, 20.10, 13.08, 12.72; IR (film,
cm.sup.-1) 2942, 1866, 1726, 1452, 1407, 1372, 1321, 1276, 1210,
1123, 1106, 1057, 1046, 1006, 931, 876, 756, 707; HRMS (El, m/z)
calcd for C.sub.40H.sub.57NO.sub.10Na (M+Na) 734.3875, found
734.3855; Anal (C.sub.40H.sub.57NO.sub.10) C, H.
Example 10
Synthesis of tertiary alcohol
primary succinate ester 9
To a solution of bis-trioxane vicinal diol 5 (52.9 mg, 0.085 mmol)
in anhydrous methylene chloride (3.0 mL) was added succinic
anhydride (25.5 mg, 0.255 mmol) and 4-(dimethylamino)-pyridine
(10.4 mg, 0.085 mmol). The reaction was stirred for 24 hours at
room temperature, at which time TLC analysis confirmed full
consumption of starting material. The reaction mixture was then
poured into a mixture of methylene chloride (30 mL) and saturated
NH.sub.4Cl solution (30 mL). Organics were extracted with
methylene chloride (3.times.20 mL), washed with brine, dried
(MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 2-propanol/methylene
chloride/ethyl acetate (1:3:18) isolated tertiary alcohol primary
succinate ester 9 as a white solid (52.0 mg, 0.071 mmol, 85%).
Mp=95-97.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.38 (s, 1H), 5.34 (s, 1H), 4.61-4.52 (m, 2H), 4.29 (Abq, 2H,
J.sub.AB=18.8, .DELTA..nu..sub.AB=11.6), 2.72-2.66 (m, 4H),
2.58-2.50 (m, 2H), 2.36-2.24 (m, 2H), 2.04-1.58 (m, 13H),
1.46-1.18 (m, 11 H), 1.40 (s, 3H), 1.39 (s, 3H), 0.95 (d, 6H,
J=6.0), 0.88 (d, 3H, J =7.6), 0.87 (d, 3H, J=7.6), 0.98-0.86 (m,
2H); .sup.13C NMR (100 MHz, CDCl.sub.3) 6176.4, 171.7, 103.2,
102.9, 89.6, 89.0, 81.1, 81.0, 73.3, 70.6, 70.3, 68.6, 52.1, 51.9,
44.1, 43.7, 37.5, 36.6, 36.5, 36.3, 35.1, 34.4, 34.3, 30.8, 30.7,
29.2, 29.1, 25.9, 25.8, 24.8, 24.7, 20.2, 20.1, 12.8, 12.5; IR
(film, cm.sup.-1) 3502, 2950, 2872, 1737, 1713, 1453, 1378, 1208,
1168, 1106, 1054, 1009, 942, 878, 844, 735; HRMS(ES) m/z calcd for
C.sub.38H.sub.58O.sub.13Na (M+Na) 745.3769, found 745.3726;
[.alpha.].sub.D.sup.23.5 56.6 (CHCl.sub.3, c=0.16); Anal
(C.sub.38H.sub.58O.sub.13) C, H.
Example 11
Synthesis of bis-trioxane
.beta.-hydroxysulfide ester 10a
To a solution of bis-trioxane epoxide 6 (80.0 mg, 0.132 mmol) in
anhydrous diethyl ether (10.0 mL) was added methyl
4-mercaptobenzoate (44.4 mg, 0.264 mmol) and neutral aluminum
oxide (1.0 g, type W 200 super I, Woelm Pharma, Germany). The
resulting slurry was stirred at room temperature for 3 hours, at
which time TLC analysis confirmed full consumption of starting
material. The reaction mixture was then filtered through a pad of
celite and the remaining solid was washed with ethyl acetate
(2.times.30 mL) before concentration of the organics in vacuo.
Flash column chromatography on silica eluting with 25% ethyl
acetate/hexanes isolated bis-trioxane p-hydroxysulfide ester 10a
as a sticky solid (81.2 mg, 0.105 mmol, 80%). .sup.1H NMR (400
MHz, CDCl.sub.3) .delta. 7.67 (ABq, 4H, J.sub.AB=8.4,
.DELTA..nu..sub.AB=154.4), 5.36 (s, 1H), 5.35 (s, 1H), 4.69 (dd,
1H, J=10.4, J=6.0), 4.69 (dd, 1H, J=10.0, J=6.0), 3.88 (s, 3H),
3.52 (ABq, 2H, J.sub.AB=12.4, .DELTA..nu..sub.AB=44.4), 2.65-2.55
(m, 1H), 2.52-2.42(m, 1H), 2.34-2.24 (m, 2H), 2.08-1.58 (m, 12H),
1.46-1.18 (m, 10H), 1.36 (s, 3H), 1.31 (s, 3H), 0.94 (d, 3H,
J=6.0), 0.85 (d, 3H, J=6.8), 0.84 (d, 3H, J=7.2), 0.98-0.86 (m,
2H). .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.166.9, 145.0,
129.6, 127.7, 126.4, 102.9, 102.8, 89.7, 89.3, 81.1, 81.0, 74.9,
70.8, 70.5, 52.1, 51.9, 43.9, 43.6, 42.4, 38.3, 37.4, 36.5, 36.4,
36.1, 34.4, 34.3, 30.8, 30.7, 26.0, 25.9, 24.8, 24.7, 20.1, 20.0,
12.7, 12.4; IR (film, cm.sup.-1) 3498, 2951, 2876, 1721, 1594,
1430, 1377, 1276, 1182, 1110, 1054, 1008, 942, 880, 845, 762, 736.
Example 12
Synthesis of bis-trioxane
P-hydroxysulfone ester 10b
To a solution of bis-trioxane .beta.-hydroxysulfide ester 10a
(40.0 mg, 0.052 mmol) in tetrachloromethane (1.5 mL), acetonitrile
(1.5 mL) and H.sub.2O (2.3 mL) was added ruthenium (III) chloride
hydrate (catalytic) and periodic acid (23.7 mg, 0.104 mmol, 2.0)
(on addition of ruthenium chloride the solution turned black). On
stirring for 30 minutes at room temperature, diethyl ether (30 mL)
was added and the reaction was stirred for a further 10 minutes.
The reaction mixture was then dried (MgSO.sub.4), filtered through
a pad of celite and the remaining solid was washed with ethyl
acetate (30 mL). The organics were then concentrated in vacuo and
flash column chromatography on silica eltuting with 30% ethyl
acetate/hexanes isolated bis-trioxane .beta.-hydroxysulfone ester
10b as a white solid (32.0 mg, 0.040 mmol, 76%).
Mp=115-117.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
8.21 (ABq, 4H, J.sub.AB=8.4, .DELTA..nu..sub.AB=73.6), 5.70 (s,
1H), 5.36 (s, 1H), 5.19 (dd, 1H, J=10.8, J=6.0), 4.88 (s, 1H),
4.58 (dd, 1H, J=9.6, J=6.4), 3.95 (s, 3H), 3.81 (ABq, 2H,
J.sub.AB=13.6, .DELTA..nu..sub.AB=278.4), 2.90-2.82 (m, 1H),
2.70-2.56 (m, 2H), 2.43-2.30 (m, 2H), 2.20-1.20 (m, 16H), 1.54 (s,
3H), 1.24 (s, 3H), 0.96 (d, 6H, J =6.0), 0.93 (d, 3H, J=8.0), 0.88
(d, 3H, J=7.6), 0.98-0.86 (m, 2H); .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 165.8, 145.3, 134.3, 129.9, 128.5, 103.6,
102.8, 90.1, 88.5, 81.2, 73.6, 71.6, 71.1, 60.1, 52.6, 52.5, 51.8,
45.0, 43.3, 39.5, 37.5, 37.3, 36.5, 34.5, 34.3, 30.5, 30.4, 26.4,
26.0, 25.0, 24.8, 24.6, 24.3, 20.3, 20.0, 13.7, 11.9; IR (film,
cm.sup.-1) 3458, 2951, 2875, 1731, 1435, 1377, 1320, 1280, 1153,
1105, 1051, 1015, 911, 880, 733; HRMS(ES) mlzcalcd for
C.sub.42H.sub.60O.sub.13SNa (M+Na) 827.3646, found 827.3661.
Example 13
Synthesis of bis-trioxane
.beta.-hydroxysulfone benzoic acid 10c
A solution of bis-trioxane .beta.-hydroxysulfone ester 10b (19.7
mg, 0.024 mmol) in 2.5% KOH/MeOH (1.0 mL) was stirred vigorously
at room temperature for three hours, at which time TLC analysis
confirmed complete consumption of starting material. The solution
was then evaporated to dryness in vacuo, before the addition of
water (10 mL). This solution was acidified with acetic acid until
pH=4.0 was attained and organics were then extracted with ethyl
acetate (2.times.30 mL), dried (MgSO.sub.4) and concentrated in
vacuo. Flash column chromatography on silica eluting with
2-propanol/methylene chloride/ethyl acetate (1:3:18) isolated
bis-trioxane .beta.-hydroxysulfone benzoic acid 10c as a white
solid (14.7 mg, 0.019 mmol, 79%). Mp=143-145.degree. C.;
[.alpha.].sub.D.sup.23.9 105.2 (CHCl.sub.3, c=0.07); .sup.1H NMR
(400 MHz, CDCl.sub.3) .delta. 8.21 (ABq, 4H, J.sub.AB=8.4,
.DELTA..nu..sub.AB=76.4), 5.71 (s, 1H), 5.38 (s, 1H), 5.19 (dd,
1H, J=10.8, J=6.4), 4.63 (dd, 1H, J=9.2, J=6.0 Hz), 3.82 (ABq, 2H,
J.sub.AB=13.6, .DELTA..nu..sub.AB=266.4 Hz), 2.85-2.82 (m, 1H),
2.70-2.56 (m, 2H), 2.43-2.30 (m, 2H), 2.20-1.20 (m, 22H, including
two singlets at 1.56 and 1.25), 0.96 (d, 6H, J=6.0), 0.93 (d, 3H,
J=8.0), 0.88 (d, 3H, J=7.6), 0.98-0.86 (m, 2H); .sup.13C NMR (100
MHz, CDCl.sub.3) .delta. 168.0, 145.7, 133.5, 130.4, 128.5, 103.8,
102.9, 90.1, 88.7, 81.3, 73.7, 71.8, 71.2, 60.2, 52.6, 51.9, 44.9,
43.3, 39.4, 37.5, 37.4, 37.3, 36.5, 34.5, 34.3, 30.6, 30.5, 26.1,
25.9, 25.0, 24.8, 24.5, 24.4, 20.2, 20.0, 13.6, 11.9; IR (film,
cm.sup.-1) 3459, 2939, 2875, 1723, 1432, 1403, 1378, 1319, 1300,
1228, 1154, 1099, 1051, 1015, 911, 877, 732, 616; HRMS(ES) m/z
calcd for C.sub.41H.sub.58O.sub.13SNa (M+Na) 813.3490, found
813.3500; Anal (C.sub.41H.sub.58O.sub.13) C, H.
Example 14
Synthesis of bis-trioxane styryl
tertiary alcohol 11a
A solution of styryllithium was prepared by adding t-BuLi (1.7 M
in hexanes, 1.2 ml, 2.04 mmol) to a solution of 4-bromostyrene
(0.13 mL, 1 mmol) in anhydrous diethyl ether (5 mL). The resulting
deep red solution was stirred for 30 minutes to ensure complete
formation of styryllithium. To a solution of bis-trioxane ketone 7
(30 mg, 0.051 mmol) in anhydrous tetrahydrofuran was added the
solution of styryllithium (0.35 ml, .about.0.07 mmol) at
-78.degree. C. and the reaction was stirred for 30 minutes, at
which time TLC analysis confirmed full consumption of starting
material. Saturated ammonium chloride solution (5 mL) was added
and organics were extracted with methylene chloride (3.times.20
mL), dried (MgSO.sub.4) and concentrated in vacuo. Gradient column
chromatography on silica eluting with 10 and then 15% ethyl
acetate/petroleum ether isolated bis-trioxane styryl tertiary
alcohol 11a as a viscous oil (26 mg, 0.037 mmol, 74%). .sup.1H NMR
(400 MHz, CDCl.sub.3) .delta. 7.45 (d, J=8.4, 2H), 7.35 (d, J=8.4,
2H), 6.68 (dd, J=10.9, J=17.6, 1 H), 5.70 (d, J=17.6, 1 H), 5.35
(s, 2H), 5.2 (d, J=10.9, 2H), 4.50-4.40 (m, 1H), 4.25-4.12 (m,
1H), 2.78-2.42 (m, 4H), 2.38-1.60 (m, 14H), 1.48-1.20 (m, 14H),
1.00-0.80 (m, 14H).
Example 15
Synthesis of bis-trioxane
tertiary alcohol benzoic acid 11b
To a solution of bis-trioxane styryl tertiary alcohol 11a (20 mg,
0.028 mmol) in acetone (3 mL) was added KMnO.sub.4 (large excess)
as a solid. The reaction was stirred at room temperature for 6
hours, at which time TLC analysis confirmed full consumption of
starting material. 2-propanol was added to quench any excess
KMnO.sub.4 and the reaction mixture was concentrated in vacuo.
Ethyl acetate (10 mL) and water (10 mL) were added and organics
were extracted with ethyl acetate (3.times.10 mL), dried
(MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 90% ethyl acetate/petroleum
ether isolated bis-trioxane tertiary alcohol benzoic acid 11b as a
white solid (19 mg, 0.014 mmol, 50%). .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 7.80 (d, 2H, J=8.4), 7.39 (d, 2H, J=8.4), 5.36
(s, 2H), 4.40-4.32 (m, 1H), 4.12-4.06 (m,1H), 2.80-2.42 (m, 4H),
2.40-2.10 (m, 3H), 2.10-1.60 (m, 15H), 1.48-1.20 (m, 14H),
1.00-0.80 (m, 14H); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.
167.4, 132.5, 130.6, 130.0, 127.7, 104.7, 104.6, 90.5, 89.9, 82.3,
82.1, 78.4, 74.1, 73.6, 54.1, 53.8, 46.4, 45.9, 43.4, 39.8, 38.6,
38.5, 37.8, 37.7, 35.9, 35.8, 32.1, 31.9, 26.4, 26.1, 26.0, 25.9,
25.8, 25.7, 20.8, 20.7, 13.9, 13.6; HRMS(ES) m/z calcd for
C.sub.40H.sub.56O.sub.11Na (M+Na) 735.3715, found 735.3717.
Example 16
Synthesis of bis-trioxane primary
alcohol isonicotinate N-oxide 13
To a stirring suspension of bis-trioxane primary alcohol 4 (0.14
g, 0.24 mmol) and commercially available (Aldrich) isonicotinic
acid N-oxide (0.11 g, 0.76 mmol) in anhydrous methylene chloride
(10 mL) was added 4-(dimethylamino)-pyridine (0.11 g, 0.93 mmol)
and 1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(0.17 g, 0.90 mmol). A further 5 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 4 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (10 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.30 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a colorless oil (0.23 g). Gradient column
chromatography on silica (crude was dry-loaded) eluting firstly
with 70% ethyl acetate/petroleum ether and then with 80% ethyl
acetate/petroleum ether isolated bis-trioxane primary alcohol
isonicotinate N-oxide 13 as a white solid (0.17 g, 0.23 mmol,
98%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 8.22 (d, 2H,
J=7.3), 7.89 (d, 2H, J =7.3), 5.32 (s, 1H), 5.29 (s, 1H), 4.52 (s,
1H), 4.51 (s, 1H), 4.51-4.54 (m, 1H), 4.39-4.32 (m, 1H), 2.67 (st,
1H, J=7.0), 2.57 (st, 1H, J=7.0), 2.42-2.26 (m, 3H), 2.07-1.97 (m,
2H), 1.97-1.85 (m, 2H), 1.84-1.74 (m, 4H), 1.70 -1.47 (m, 6H),
1.41-1.19 (m, 14H, including two singlets at 1.40 and 1.39),
1.00-0.91 (m, 2H), 0.96 (d, 3H, J=5.6), 0.95 (d, 3H, J=5.6), 0.88
(d, 3H, J=6.9), 0.86 (d, 3H, J=6.9); .sup.13C NMR (CDCl.sub.3, 100
MHz) .delta. 163.27, 139.35 (2), 127.26, 126.39 (2), 103.10,
102.80, 89.64, 89.01, 81.12, 81.09, 72.99, 70.52, 68.37, 52.22,
52.01, 44.21, 43.97, 37.56, 37.49, 36.63, 36.53, 34.40, 34.36,
33.98, 30.95, 30.58, 30.52, 29.68, 26.03, 25.98. 24.92, 24.88,
24.77, 24.75, 20.16, 20.07, 12.96, 12.62; HRMS (El, m/z) for
C.sub.40H.sub.57NO.sub.11Na requires 750.3824, found 750.3845; IR
(film, cm.sup.-1) 2931, 2871, 1719, 1609, 1448, 1373, 1261, 1156,
1108, 1049, 1037, 1008, 925, 732; Mp. 114-122.degree. C.;
[.alpha.].sub.D.sup.231 51.7 (CHCl.sub.3, c=0.67); Anal
(C.sub.40H.sub.59NO.sub.12) C, H, N.
Example 17
Synthesis of bis-trioxane
diphenyl phosphate 14
To a stirring solution of bis-trioxane primary alcohol 4 (8.0 mg,
0.013 mmol) in anhydrous methylene chloride (0.5 mL) was added
diphenyl chlorophosphate (10 .mu.L, 0.048 mmol) and pyridine (20
.mu.L, 0.247 mmol). A further 1 mL of anhydrous methylene chloride
was used to wash down the inside walls of the flask and the
reaction was stirred at room temperature. TLC analysis after 18
hours showed a substantial amount of starting material still
present. A second portion of diphenyl chlorophosphate (50 .mu.L,
0.241 mmol) and 4-(dimethylamino)-pyridine (15.0 mg, 0.123 mmol)
were added and the reaction stirred at room temperature for a
further 2 hours. At this time, TLC analysis confirmed that no
starting material remained. Water (10 mL), 3M HCl (2 mL) and
methylene chloride (10 mL) were added and organics were extracted
with methylene chloride (3.times.15 mL), dried (Na.sub.2SO.sub.4)
and concentrated in vacuo to give a yellow oil. Gradient column
chromatography on silica (crude was dry-loaded) eluting firstly
with 20% and then 25% ethyl acetate/petroleum ether isolated
bis-trioxane diphenyl phosphate 14 as a cloudy white oil (10.3 mg,
0.012 mmol, 93%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 7.33
(t, 4H, J=7.7), 7.28-7.22 (m, 4H), 7.17 (t, 2H, J=7.7), 5.30 (s,
1H), 5.29 (s, 1H), 4.58-4.51 (m, 1H), 4.50-4.37 (m, 2H), 4.25 (dd,
1H, J=10.1, 2.05-1.97 (m, 2H), 1.95-1.79 (m, 4H), 1.79-1.33 (m,
16H, including two singlets at 1.40 and 1.37), 1.32-1.17 (m, 6H),
0.98-0.78 (m, 14H); .sup.13C NMR (CDCl.sub.3, 100 MHz) .delta.
150.68 (d, 2, J=7.2), 129.67 (4), 125.11 (2), 120.17 (d, 2,
J=3.9), 120.12 (d, 2, J=3.9), 103.19, 102.78, 89.45, 88.73, 81.14,
81.10, 73.80, 71.92 (d, J=7.0), 70.80, 52.39, 52.11, 44.47, 44.09,
37.40, 37.28, 36.64, 36.58, 35.33 (d, J=7.7), 34.46, 34.42, 30.49,
30.42, 30.15, 29.38, 26.11, 26.05, 24.86, 24.79, 24.74, 24.61,
20.19, 20.09, 13.17, 12.61; .sup.31P NMR (162 MHz) .delta. -11.77;
HRMS (El, m/z) for C.sub.46H.sub.63O.sub.12PNa requires 861.3949,
found 861.3879; IR (film, cm.sup.-1) 2919, 2861, 1589, 1485, 1455,
1376, 1290, 1220, 1190, 1108, 1008, 944, 767, 686;
[.alpha.].sub.D.sup.24.1 67.6 (CHCl.sub.3, c=0.26).
Example 18
Synthesis of bis-trioxane primary
alcohol nicotinate N-oxide 15
To a stirring suspension of bis-trixane primary alcohol 4 (19.7
mg, 0.033 mmol) and nicotinic acid N-oxide (13.1 mg, 0.094 mmol)
in anhydrous methylene chloride (1 mL) was added
4-(dimethylamino)-pyridine (14.1 mg, 0.115 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(21.4 mg, 0.112 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 2 hours 30 minutes, at which
time TLC analysis showed full consumption of starting material.
Water (5 mL), 3M HCI solution (5 mL) and methylene chloride (5 mL)
were added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a white cloudy oil (33.2 mg). Gradient column
chromatography on silica (crude was dry-loaded) eluting firstly
with ethyl acetate and then with 3% methanol/ethyl acetate
isolated bis-trioxane primary alcohol nicotinate N-oxide 15 as a
glassy solid. Treatment with hexanes (2.times.10 mL) (followed by
drying overnight under high vacuum) gave a white solid (23.6 mg,
0.032 mmol, 99%). .sup.1H NMR (CDCl.sub.3, 400 MHz) 8 8.76 (s, br,
1H), 8.33 (d, 1H, J=6.3), 7.87 (d, 1H, J=7.9), 7.36 (t, br, 1H,
J=7.1), 5.31 (s, 1H), 5.27 (s, 1H), 4.61-4.51 (m, 2H), 4.46 (dd,
1H, J=10.0, J=6.2), 4.35 (dd, 1H, J=10.0, J=6.2), 2.65 (q, 1H,
J=6.8), 2.55 (q, 1H, J=6.8), 2.40-2.24 (m, 3H), 2.06-1.71 (m, 8H),
1.70-1.47 (m, 6H), 1.42-1.18 (m, 14H, including two singlets at
1.40 and 1.38), 0.99-0.89 (m, 8H), 0.86 (apparent triplet, 6H,
J=7.0); .sup.13C NMR (CDCl.sub.3, 100 MHz) .delta. 162.65, 142.15,
140.12, 130.57, 126.41, 125.68, 103.01, 102.77, 89.63, 89.02,
81.12, 81.10, 73.00, 70.36, 68.34, 52.18, 51.98, 44.16, 43.93,
37.47, 37.45, 36.62, 36.51, 34.36, 34.33, 33.95, 30.96, 30.59,
30.56, 30.30, 25.99, 25.96, 24.90, 24.86, 24.75, 24.66, 20.16,
20.07, 12.92, 12.60; HRMS (El, m/z) for
C.sub.40H.sub.57NO.sub.11Na requires 750.3824, found 750.3858; IR
(film, cm.sup.-1) 2931, 2870, 1727, 1435, 1375, 1296, 1223, 1106,
1043, 1008, 879, 749; Mp. 104-108.degree. C. (morphological change
observed beginning at -80.degree. C.); [.alpha.].sub.D.sup.24.4
49.7 (CHCl.sub.3, c=0.205); Anal (C.sub.40H.sub.57NO.sub.11+0.5
H.sub.2O) C, H, N.
Example 19
Synthesis of bis-trioxane
phosphonic acid monoester 16
To a solution of methylphosphonic dichloride (32.2 mg, 0.242 mmol)
in anhydrous methylene chloride (1 mL) was added
4-(dimethylamino)-pyridine (5.2 mg, 0.043 mmol). The mixture was
stirred at room temperature for five minutes before addition of
bis-trioxane primary alcohol 4 (25.7 mg, 0.042 mmol) in anhydrous
methylene chloride (1.25 mL) by canula. On stirring at room
temperature for 1 hour 45 minutes, TLC analysis showed a large
amount of starting material remaining and so a second portion of
4-(dimethylamino)-pyridine (5.2 mg, 0.043 mmol) was added.
Continued stirring for a further 2 hours followed by TLC analysis
showed that starting material still remained. A third portion of
4-(dimethylamino)-pyridine (10.0 mg, 0.082 mmol) was added and the
reaction was stirred at room temperature. After 15 hours, TLC
analysis confirmed full consumption of starting material and
pyridine (0.2 mL, 2.47 mmol) was added and the mixture stirred
vigorously for 1 hour before careful addition of 3M HCl (3 mL,
.about.9 mmol) and continued stirring for a further 1 hour.
Methylene chloride (5 mL) and water (5 mL) were added and organics
were extracted with methylene chloride (3.times.10 mL), dried
(Na.sub.2SO.sub.4) and concentrated in vacuo to give a white
cloudy oil (34.7 mg). Gradient column chromatography on silica
(crude was dry-loaded) eluting with 10% then 30% methanol/ethyl
acetate isolated bis-trioxane phosphonic acid monoester 16 as a
glassy solid. Treatment with hexanes (2.times.10 mL) and then
acetonitrile (3.times.10 mL) (followed by drying overnight under
high vacuum) gave a white solid (22.9 mg, 0.033 mmol, 79%).
.sup.1H NMR (CD.sub.3OD, 400 MHz) .delta. 5.39 (s, br, 2H), 4.30
(dd, 1H, J=10.4, J=6.1), 4.20 (dd, 1H, J=10.4, J=6.1), 3.99-3.87
(m, 2H), 2.70-2.54 (m, 2H), 2.29 (t, br, 2H, J =13.9), 2.10-1.99
(m, 3H), 1.97-1.87 (m, 3H), 1.86-1.75 (m, 3H), 1.68 (d, br, 2H,
J=13.2), 1.61-1.33 (m, 16H, including singlet at 1.35), 1.30-1.17
(m, 5H, including doublet (J=16.6) at 1.27), 1.02-0.94 (m, 2H),
0.97 (d, br, 6H, J=6.1), 0.90 (dd, 6H, J=7.5, J=2.8); .sup.13C NMR
(CD.sub.3OD, 100 MHz) .delta. 104.75, 104.53, 90.54, 90.22, 82.52,
82.49, 75.60, 74.84, 67.77 (d, J=5.4), 54.14, 54.00, 46.28, 46.08,
38.62, 38.60, 37.81, 37.77, 37.52 (d, J=7.6), 35.91, 35.87, 32.12,
32.10, 31.48 (2), 26.46 (2), 26.14, 26.08, 26.01, 25.99, 20.81,
20.74, 13.90, 13.66, 12.56 (d, J=139.1); .sup.3P NMR (CD.sub.3OD,
162 MHz) .delta. 22.07; HRMS (El, m/z) for
C.sub.35H.sub.56O.sub.11PNa.sub.2 requires 729.3350, found
729.3370; IR (film, cm.sup.-1) 2940, 2862, 1449, 1372, 1196, 1188,
1090, 1037, 1008, 937, 896, 878, 826, 732; Mp. 142-147.degree. C.;
[.alpha.].sub.D.sup.23.4 8.9 (CHCl.sub.3, c=3.09).
Example 20
Synthesis of bis-trioxane
secondary alcohol 17
Bis-trioxane ketone 7 (10 mg, 0.016 mmol) was dissolved in MeOH (1
mL) and the solution was cooled to 0.degree. C. To this cooled
solution was added NaBH.sub.4 (4.2 mg, 0.112 mmol, 7.7 eq.) in 4
portions. The reaction mixture was then stirred for 1 hour and
quenched with dropwise addition of 1% AcOH--MeOH until neutral pH
was attained. The reaction mixture was then concentrated in vacuo
and the crude product charged onto a silica column. Column
chromatography gave bis-trioxane secondary alcohol 17 as a white
solid (8 mg, 84%). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 5.37
(s, 1H), 5.31 (s, 1H), 4.54-4.40 (m, 2H), 4.10-3.99 (bm,1H), 3.75
(s,1H), 2.76-2.60 (m, 2H), 2.38-2.24 (m, 2H), 2.08-1.20 (m, 28H),
0.96-0.84 (m, 14H); .sup.13CNMR (100 MHz, CDCl.sub.3) .delta.
133.9, 133.7, 128.8, 128.6, 128.5, 103.3, 89.0, 88.9, 81.1, 76.2,
72.4, 71.3, 52.2, 52.4, 52.3, 44.5, 44.2, 37.6, 37.5, 36.6, 36.5,
36.3, 36.2, 34.6, 34.5, 30.6, 30.4, 26,2, 26.1, 24.9, 24.8, 24.7,
20.3, 13.2, 13.1; HRMS (El, m/z) for
C.sub.33H.sub.52O.sub.9Na.sup.+ required 615.3503, found 615.3466.
Example 21
Synthesis of bis-trioxane vicinal
diol isonicotinate N-oxide 18
To a stirring suspension of bis-trioxane vicinal diol 5 (19.4 mg,
0.031 mmol) and commercially available (Aldrich) isonicotinic acid
N-oxide (14.5 mg, 0.104 mmol) in anhydrous methylene chloride (1
mL) was added 4-(dimethylamino)-pyridine (14.5 mg, 0.119 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(23.0 mg, 0.120 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 1 hour 30 minutes, at which
time TLC analysis showed full consumption of starting material.
Water (5 mL), 3M HCl solution (5 mL) and methylene chloride (5 mL)
were added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a colorless oil. Gradient column chromatography on
silica (crude was dry-loaded) eluting firstly with 100% ethyl
acetate and then with 3% methanol/ethyl acetate isolated
bis-trioxane vicinal diol isonicotinate N-oxide 18 as a colorless
oil. Treatment with methylene chloride (2.times.10 mL) and then
hexanes (2.times.10 mL) (followed by drying overnight under high
vacuum) gave a white solid (22.7 mg, 0.031 mmol, 99%). .sup.1H NMR
(400 MHz, CDCl.sub.3) .delta. 8.21 (d, 2H, J =7.3), 7.92 (d, 2H,
J=7.3), 5.33 (s, 1H), 5.31 (s, 1H), 4.75 (dd, 1H, J=10.3, J=6.2),
4.65-4.51 (m, 3H), 4.34 (s, br, 1H), 2.58 (qt, 1H, J=7.0), 2.56
(qt, 1H, J=7.0), 2.30 (t, br, 2H, J=13.3), 2.08-1.85 (m, 7H),
1.83-1.60 (m, 7H), 1.42-1.17 (m, 14H, including two singlets at
1.40 and 1.37), 0.99-0.93 (m, 8H), 0.89 (apparent triplet, br, 6H,
J=7.7); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 163.04, 139.27
(2), 127.39, 126.45 (2),102.86, 102.84, 89.74, 89.41, 81.02 (2),
73.62, 70.04, 69.85, 51.91, 51.83, 43.64, 43.52, 37.58, 37.55,
36.75, 36.53, 36.46, 35.38 (2), 34.27, 34.25, 30.86, 30.82, 25.92,
25.87, 24.85 (2), 24.77 (2), 20.08, 20.02, 12.50, 12.39; HRMS (El,
m/z) for C.sub.40H.sub.57NO.sub.12Na.sup.+ requires 766.3773,
found 766.3770; IR (film, cm.sup.-1) 3483, 2931, 2861, 1719, 1608,
1443,1377, 1257, 1165, 1102, 1008, 908, 732; Mp. 114-118.degree.
C.
Example 22
Synthesis of bis-trioxane
isobutyric acid 19
To a solution of bis-trioxane primary alcohol 4 (132 mg, 0.218
mmol) in ethyl acetate (4 mL), acetonitrile (4.0 mL) and H20 (1.3
mL) was added ruthenium (III) chloride hydrate (4.5 mg, 0.022
mmol) and sodium periodate (326 mg, 1.53 mmol, 7.0) (on addition
of ruthenium chloride the solution turned black). After stirring
for 30 mins at room temperature (the color of solution turned to
pale orange), the reaction mixture was poured into a mixture of
ethyl acetate (30 mL) and saturated aqueous NH.sub.4Cl solution
(30 mL). Organics were extracted with ethyl acetate (2.times.30
mL), dried (MgSO.sub.4), filtered through a pad of celite and
concentrated in vacuo. Flash column chromatography on silica
eluting with 1% acetic acid in 30% ethyl acetate/hexane isolated
bis-trioxane isobutyric acid 19 as a white solid (126 mg, 0.204
mmol, 94%). Mp=105-110.degree. C. Further purification by medium
pressure liquid chromatography (MPLC: LiChroprep Si60
(40-63.quadrature.m)-EM Science) with the same solvent system (1%
acetic acid in 30% ethyl acetate/hexane) removed unknown
impurities and gave a white solid (118 mg, 0.190 mmol, 87%);
Mp=110-113.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.30 (s,1H), 5.29 (s, 1H), 4.30-4.20 (m, 2H), 2.92-2.84 (m, 1H),
2.75-2.55 (m, 2H), 2.35-2.23 (m, 2H), 2.15-1.95 (m, 3H), 1.94-1.50
(m,11H), 1.46-1.20 (m, 15H, including two singlets at 1.39 and
1.38), 0.94 (d, 6H, J=6.0), 0.86 (d, 6H, J=7.6), 0.98-0.86 (m,
2H); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 179.9, 103.3,
103.1, 89.0, 88.6, 81.1, 81.0, 74.3, 72.8, 52.3, 52.2, 44.4, 44.2,
41.8, 37.4, 37.3, 36.5, 36.5, 34.4, 31.5, 31.4, 30.3, 30.2, 25.9,
25.8, 24.7, 24.6, 20.2, 20.1, 13.1, 12.7; IR (film, cm.sup.-1)
3500 (br), 2940, 2875, 1705, 1450, 1377, 1279, 1187, 1094, 1053,
1011, 941, 877, 826, 734; HRMS(ES) m/z calcd for
C.sub.34H.sub.52O.sub.10Na (M+Na) 643.3457, found 643.3470.
Example 23
Synthesis of bis-trioxane
P-hydroxy O-allyl ether 20
To a suspension of KH (.about.35% in mineral oil, 16 mg
(.about.5.6 mg actual), 0.14 mmol) in anhydrous diethyl ether (1.0
mL) at 0.degree. C. was added a solution of bis-trioxane vicinal
diol 5 (28.9 mg, 0.046 mmol) in diethyl ether (0.7 mL). The
reaction was stirred for 30 mins (to ensure complete formation of
the alkoxide) before addition of allyl bromide (0.012 mL, 0.14
mmol) and 18-crown-6 (2.4 mg, 0.009 mmol). The reaction was then
allowed to warm to room temperature and was stirred until TLC
analysis showed no starting material remaining. The reaction
mixture was poured into a mixture of diethyl ether (20 mL) and
saturated aqueous NH.sub.4Cl solution (20 mL) and organics were
extracted with diethyl ether (3.times.10 mL), washed with brine,
dried (MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 20% ethyl acetate/hexanes
isolated bis-trioxane P-hydroxy O-allyl ether 20 as a sticky solid
(22.3 mg, 0.034 mmol, 74%); .sup.1H NMR (400 MHz, CDCl3) 6
5.98-5.88 (m, 1H), 5.32 (s, 2H), 5.25 (ddd, 1H, J=17.2, J=3.6,
J=1.6), 5.12 (apparent doublet, br,.sub.1 H, J=10.4), 4.33-4.28
(m, 1H), 4.23-4.17 (m, 1H), 4.02-3.90 (m, 2H), 3.60-3.53 (m, 2H),
2.75-2.60 (m, 2H), 2.35-2.25 (m, 2H), 2.10-1.18 (m, 28H, including
two singlets at 1.40 and 1.39); 0.94 (d, 6H, J=6.0), 0.86 (d, 3H,
J=7.6), 0.84 (d, 3H, J=7.6), 0.98-0.86 (m, 2H); .sup.13C NMR (100
MHz, CDCl.sub.3) .delta. 135.6, 116.4, 103.1, 103.0, 89.2, 88.6,
81.1, 81.0, 73.9, 73.8, 72.1, 71.5, 71.3, 52.4, 52.2, 44.5, 44.1,
37.4, 36.6, 35.8, 35.0, 34.5, 34.4, 30.7, 30.7, 26.1, 26.0, 24.8,
24.7, 20.2, 20.1, 13.2, 12.9; IR (film, cm.sup.-1) 3506, 2953,
2925, 2874, 1452, 1376,1222, 1190, 1127, 1093, 1053, 1011, 942,
878, 843, 731; HRMS(ES) m/z calcd for C.sub.37H.sub.58NaO.sub.10
(M+Na) 685.3922, found 685.3915.
Example 24
Synthesis of bis-trioxane
P-hydroxy O-acetic acid 21
To a solution of bis-trioxane .beta.-hydroxy O-allyl ether 20
(40.3 mg, 0.061 mmol) in ethyl acetate (1.2 mL), acetonitrile (1.2
mL) and water (0.4 mL) was added ruthenium (III) chloride hydrate
(catalytic) and sodium periodate (65.0 mg, 0.304 mmol) (on
addition of ruthenium chloride the solution turned black). The
reaction was stirred at room temperature for 30 mins (the color of
solution turned to pale orange), at which time TLC analysis
confirmed complete consumption of starting material. The reaction
mixture was poured into a mixture of ethyl acetate (20 mL) and
saturated aqueous NH.sub.4Cl solution (20 mL) and organics were
extracted with ethyl acetate (2.times.20 mL), dried (MgSO.sub.4),
filtered through a pad of celite and concentrated in vacuo. Flash
column chromatography on silica eluting with 1% acetic acid in 4%
methanol/methylene chloride isolated bis-trioxane p-hydroxy
O-acetic acid 21 as a white solid (5.3 mg, 0.008 mmol, 13%).
Mp=85-89.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.35 (s, 1H), 5.34 (s, 1H), 4.82-4.76 (m, 1H), 4.52-4.46 (m, 1H),
4.25 (d, 1H, J=17.0), 4.09 (d, 1H, J=17.0), 3.80 (d, 1H, J=9.4),
3.67 (d, 1H, J=9.4), 1.40 (s, 3H), 1.38 (s, 3H), 0.94 (d, 6H,
J=6.0), 0.86 (d, 3H, J=7.6), 0.84 (d, 3H, J=7.6), 0.98-0.86 (m,
2H); HRMS(ES) m/z calcd for C.sub.36H.sub.56NaO.sub.12(M+Na)
703.3664, found 703.3681.
Example 25
Synthesis of bis-trioxane primary
alcohol picolinate 22
To a solution of bis-trioxane primary alcohol 4 (29.9 mg, 0.049
mmol) in anhydrous methylene chloride (0.5 mL) was added picolinyl
chloride hydrochloride (22.1 mg, 0.124 mmol) and
4-(dimethylamino)-pyridine (34.2 mg, 0.280 mmol). A further
portion of anhydrous methylene chloride (1 mL) was added to wash
down the flask walls and the reaction was stirred at room
temperature for 18 hours, at which time TLC analysis confirmed
full consumption of starting material. Water (5 mL), saturated
NaHCO.sub.3 solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give an off-white solid. Gradient column chromatography
on silica (crude was dry-loaded) eluting with 30%, 40% and then
50% ethyl acetate/petroleum ether isolated bis-trioxane primary
alcohol picolinate 22 as a colorless oil. Treatment with methylene
chloride (2.times.10 mL) and then hexanes (2.times.10 mL)
(followed by drying overnight under high vacuum) gave a white
bubbly oil (33.1 mg, 0.047 mmol, 94%). .sup.1H NMR (CDCl.sub.3,
400 MHz) .delta. 8.74 (s, br, 1H, J=4.8), 8.12 (d,1H, J=7.8), 7.83
(dt,1H, J=7.8, J=1.7), 7.46 (dd,1H, J=7.8, J=4.8), 5.35 (s,1H),
5.33 (s, 1H), 4.62-4.54 (m, 2H), 4.44 (dd, 1H, J=10.6, J=6.0),
4.29 (dd, 1H, J=10.6, J=6.0), 2.71 (st, 1H, J=6.9), 2.61 (st, 1H,
J=6.9), 2.49-2.38 (m, br, 1H), 2.29 (dt, 2H, J=13.9, J=3.7),
2.02-1.71 (m, 7H), 1.69-1.52 (m, 6H), 1.43-1.17 (m, 15H, including
two singlets at 1.39 and 1.37), 1.00-0.81 (m, 14H); .sup.13C NMR
(CDCl.sub.3, 100 MHz) .delta. 164.85, 149.59, 148.55, 136.93,
126.54, 125.03, 103.13, 102.90, 89.24, 88.58, 81.14, 81.10, 73.59,
71.46, 68.25, 52.39, 52.16, 44.49, 44.21, 37.33, 37.26, 36.61,
36.54, 34.47, 34.43, 34.16, 30.57, 30.46, 29.93, 29.63, 26.08,
26.04, 24.91, 24.83, 24.69, 24.60, 20.20, 20.11, 13.24, 12.87;
HRMS (El, m/z) for C.sub.40H.sub.57NO.sub.10Na requires 734.3875,
found 734.3897; IR (film, cm.sup.-1) 2941, 2874, 1717, 1458, 1437,
1376, 1303, 1245, 1128, 1104, 1044, 1006, 931, 876, 743;
[.alpha.].sub.D.sup.23.9 64.5 (CHCl.sub.3, c=0.270).
Example 26
Synthesis of bis-trioxane vicinal
diol nicotinate N-oxide 23
To a stirring suspension of bis-trioxane vicinal diol 5 (26.0 mg,
0.042 mmol) and commercially available (Aldrich) nicotinic acid
N-oxide (19.9 mg, 0.143 mmol) in anhydrous methylene chloride (2
mL) was added 4-(dimethylamino)-pyridine (19.8 mg, 0.162 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(32.0 mg, 0.167 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 3 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a white solid. The crude material was pre-absorbed
on silica and gradient column chromatography on silica eluting
with 100% ethyl acetate, 5% methanol/ethyl acetate and then 10%
methanol/ethyl acetate isolated bis-trioxane vicinal diol
nicotinate N-oxide 23 as a colorless oil. Treatment with methylene
chloride (2.times.10 mL) and then hexanes (2.times.10 mL)
(followed by drying overnight under high vacuum) gave a white
solid (29.1 mg, 0.039 mmol, 94%)..sup.1H NMR (CDCl.sub.3, 400 MHz)
.delta. 8.80 (s, br, 1H), 8.33 (d, 1H, J=6.5), 7.89 (d, 1H, J=7.9
), 7.35 (dd, 1h, J=6.5, J=7.9), 5.32 (s, 1H), 5.28 (s, 1H), 4.74
(dd, J=6.2, J=10.4), 4.67-4.57 (m, 2H), 4.50 (d, 1H, J=11.2), 4.32
(s, br, 1H), 2.58 (st, 1H, J=7.0), 2.52 (st, 1H, J=7.0), 2.34-2.23
(m, 2H), 2.06-1.61 (m, 14H), 1.43-1.18 (m, 14H, including two
singlets at 1.40 and 1.36), 1.00-0.83 (m, 14H, including doublet
at 0.94 (J=5.4) and apparent triplet at 0.88 (J=7.4)); .sup.13C
NMR (CDCl.sub.3, 100 MHz) .delta. 162.38, 142.07, 140.18, 130.63,
126.53, 126.60, 102.82, 102.78, 89.79, 89.27, 81.02 (2), 73.32,
69.88, 69.82, 69.79, 51.92, 51.79, 43.65, 43.42, 37.48 (2), 36.87,
36.52, 36.43, 35.24, 34.25, 34.21, 30.85, 30.79, 25.87, 25.82,
24.83, 24.81, 24.72, 24.69, 20.08, 20.00, 12.51, 12.31; HRMS (El,
m/z) for C.sub.40H.sub.57NO.sub.12Na requires 766.3773, found
766.3817; IR (film, cm.sup.-1) 2938, 2875, 1732, 1435, 1376, 1298,
1226, 1108, 1054, 1013, 941, 842, 754, 733; Mp. 116-118.degree. C.
(morphological change observed beginning at 102.degree. C.);
[.alpha.].sub.D.sup.245 33.5 (CHCl.sub.3, c=0.10); Anal
(C.sub.40H.sub.57NO.sub.12) C, H, N.
Example 27
Synthesis of bis-trioxane
secondary alcohol isonicotinate N-oxide 24
To a stirring suspension of bis-trioxane secondary alcohol 17
(21.6 mg, 0.036 mmol) and commercially available (Aldrich)
isonicotinic acid N-oxide (16.2 mg, 0.116 mmol) in anhydrous
methylene chloride (1 mL) was added 4-(dimethylamino)-pyridine
(16.8 mg, 0.138 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(25.9 mg, 0.135 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 3 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCI solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a colorless oil (29.5 mg). Gradient column
chromatography on silica (crude was dry-loaded) eluting firstly
with 80% ethyl acetate/petroleum ether and then with 100% ethyl
acetate isolated bis-trioxane secondary alcohol isonicotinate
N-oxide 24 as a colorless oil. Treatment with methylene chloride
(2.times.10 mL) and then hexanes (2.times.10 mL) (followed by
drying overnight under high vacuum) gave a white solid (24.4 mg,
0.034 mmol, 94%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 8.18
(d, 2H, J=6.9), 7.92 (d, 2H, J=6.9), 5.48-5.39 (m, 1H), 5.35 (s,
1H), 5.31 (s, 1H), 4.46-4.37 (m, 2H), 2.65 (st, 2H, J=6.9),
2.35-2.22 (m, 2H), 2.16-1.54 (m, 13H), 1.49-1.17 (m, 15H,
including two singlets at 1.31 and 1.26), 1.00-0.80 (m, 14H,
including apparent triplet at 0.95 (J=5.6) and two doublets at
0.88 (J=7.5) and 0.83 (J=7.5)); .sup.13C NMR (CDCl.sub.3, 100 MHz)
.delta. 162.93, 139.17 (2), 127.70, 126.61 (2), 103.06, 102.99,
88.95, 88.86, 81.06 (2), 74.27, 71.73, 71.11, 52.23, 52.10, 44.21,
44.08, 37.39, 37.30, 36.51, 35.45, 34.38, 34.34, 32.72, 32.69,
30.39 (2), 25.93, 25.83, 24.72, 24.64, 24.62 (2), 20.14, 20.11,
12.99, 12.97; HRMS (El, m/z) for C.sub.39H.sub.55NO.sub.11Na
requires 736.3667, found 736.3678; IR (film, cm.sup.-1) 2937,
2873, 1717, 1611, 1445, 1376, 1265, 1163, 1094, 1054, 1011; Mp.
114-118.degree. C. (morphological change observed beginning at
103.degree. C.); [.alpha.].sub.D.sup.24.3 75.5 (CHCl.sub.3,
c=0.13); Anal (C.sub.39H.sub.55NO.sub.11) C, H, N.
Example 28
Synthesis of bis-trioxane
secondary alcohol nicotinate N-oxide 25
To a stirring suspension of bis-trioxane secondary alcohol 17
(30.7 mg, 0.052 mmol) and commercially available (Aldrich)
nicotinic acid N-oxide (21.5 mg, 0.155 mmol) in anhydrous
methylene chloride (1 mL) was added 4-(dimethylamino)-pyridine
(22.0 mg, 0.180 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(34.5 mg, 0.180 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 3 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a colorless oil. Gradient column chromatography on
silica (crude was dry-loaded) eluting firstly with 100% ethyl
acetate and then with 5% methanol/ethyl acetate isolated
bis-trioxane secondary alcohol nicotinate N-oxide 25 as a
colorless oil. Treatment with methylene chloride (2.times.10 mL)
and then hexanes (2.times.10 mL) (followed by drying overnight
under high vacuum) gave a white solid (37.5 mg, 0.052 mmol, 100%).
.sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 8.78 (s, 1H), 8.29 (d,
1H, J=6.5), 7.88 (d, 1H, J=8.0), 7.31 (dd, 1H, J=8.0, J=6.5),
5.52-5.42 (m, 1H), 5.32 (s, 1H), 5.30 (s, 1H), 4.45-4.34 (m, 2H),
2.64 (st, 2H, J=6.9), 2.34-2.21 (m, 2H), 2.16-1.53 (m, 13H),
1.49-1.15 (m, 15H, including two singlets at 1.28 and 1.27),
1.00-0.80 (m, 14H, including four doublets at 0.94 (J=6.1), 0.93
(J=6.1), 0.87 (J=7.5) and 0.83 (J=7.5); .sup.13C NMR (CDCl.sub.3,
100 MHz) .delta. 162.38, 141.93, 140.47, 130.87, 126.66, 125.45,
103.07, 102.98, 88.99, 88.77, 81.03, 81.01, 74.60, 71.93, 70.87,
52.25, 52.09, 44.22, 44.03, 37.35, 37.30, 36.52, 36.43, 34.38,
34.34, 32.93, 32.88, 30.36 (2), 25.85, 25.77, 24.73, 24.66, 24.63,
24.58, 20.13, 20.10, 13.01, 12.88; HRMS (El, m/z) for
C.sub.39H.sub.55NO.sub.11Na requires 736.3667, found 736.3715; IR
(film, cm.sup.-1) 2951, 2874, 1726, 1432, 1377, 1299, 1225, 1114,
1094, 1056, 1013, 950, 876, 822, 753; Mp. 106-110.degree. C.
(morphological change observed beginning at 98.degree. C.);
[.alpha.].sub.D.sup.24.3 63.1 (CHCl.sub.3, c=0.225); Anal
(C.sub.39H.sub.55NO.sub.11+0.5 H.sub.2O) C, H, N.
Example 29
Synthesis of bis-trioxane primary
alcohol diethyl phosphoric acid triester 26
To a stirring solution of bis-trioxane primary alcohol 4 (26.1 mg,
0.043 mmol) in anhydrous methylene chloride (2.5 mL) was added
diethylchlorophosphate (0.12 mL, 0.860 mmol) and anhydrous
pyridine (0.07 mL, 0.860 mmol). On stirring at room temperature
for 3 hrs, TLC analysis showed full consumption of starting
material. Water (2 mL), 3M HCl (3 mL) and methylene chloride (3
mL) were added and organics were extracted with methylene chloride
(3.times.15 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a yellow oil. Gradient column chromatography on
silica eluting with 40% and then 50% ethyl acetate/petroleum ether
isolated bis-trioxane primary alcohol diethyl phosphoric acid
triester 26 as a colorless oil (28.1 mg, 0.038 mmol, 88%). .sup.1H
NMR (400 MHz, CDCl.sub.3) .delta. 5.30 (s, 1H), 5.27 (s, 1H),
4.40-4.35 (m, 1H), 4.24-4.06 (m, 7H), 2.68 (st, 1H, J=7.6), 2.54
(st, 1H, J=6.8), 2.34-1.92 (m, 6H), 1.91-1.14 (m, 31H, including a
singlet at 1.38, a singlet at 1.37, and a doublet of triplets at
1.31 (J=6.8, 0.8)), 1.02-0.68 (m, 14H, including doublets at 0.93
(J=6.0), 0.84 (J=7.6) and 0.83 (J=7.6); .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 103.16, 102.74, 89.35, 89.64, 81.12, 81.08,
74.00, 71.03, 69.72 (d, J=5.8), 63.54 (d, J=6.0), 63.52 (d,
J=6.0), 52.40, 52.10, 44.50, 44.10, 37.36, 37.33, 36.61, 36.54,
35.36 (d, J=7.5), 34.46, 34.40, 30.51, 30.43, 30.10, 26.05, 25.99,
24.81, 24.74, 24.70, 24.62, 20.19, 20.07, 16.14 (2, d, J=6.8),
13.20, 12.67; .sup.31P NMR (162 MHz, CDCl.sub.3) 8 0.058; HRMS
(El, m/z) for C.sub.38H.sub.63O.sub.12PNa requires 765.3949, found
765.3981; IR (film, cm.sup.-1) 2941 (m), 2880(w), 1454(w),
1373(w), 1271 (m), 1103(m), 1037 (s), 1011 (s), 878 (w), 843 (w),
665 (w); [.alpha.].sub.D.sup.236 13.4 (CHCl.sub.3, c=0.30).
Example 30
Synthesis of bis-trioxane primary
alcohol dimethyl phosphoric acid triester 27
To a stirring solution of bis-trioxane primary alcohol 4 (21.0 mg,
0.035 mmol) in anhydrous methylene chloride (2.0 mL) was added
dimethylchlorophosphate (0.07 mL, 0.70 mmol) and anhydrous
pyridine (0.06 mL, 0.70 mmol). On stirring at room temperature for
3 hrs, TLC analysis showed full consumption of starting material.
Water (2 mL), 3M HCl (3 mL) and methylene chloride (3 mL) were
added and organics were extracted with methylene chloride
(3.times.15 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a yellow oil. Gradient column chromatography on
silica eluting with 40% and then 50% ethyl acetate/petroleum ether
isolated bis-trioxane primary alcohol dimethyl phosphoric acid
triester 27 as a colorless oil (13.6 mg, 0.020 mmol, 55%). .sup.1H
NMR (400 MHz, CDCl.sub.3) 5.32 (s, 1H), 5.29 (s, 1H), 4.45-4.35
(m, 1H), 4.28-4.17 (m, 3H), 3.78 (d, 3H, J=10.8), 3.77 (d, 3H,
J=11.2), 2.69 (st, 1H, J=7.6), 2.55 (st, 1H, J=6.4), 2.34-2.25 (m,
2H), 2.17 (s, br, 1H), 2.02-1.18 (m, 28H, including singlet at
1.37), 1.02-0.80 (m, 14H, including doublets at 0.95 (J=6.0), 0.86
(J=7.6) and 0.85 (J=7.2)); .sup.13C NMR (100 MHz, CDCl.sub.3)
.delta. 103.17, 102.77, 89.52, 88.77, 81.16, 81.14, 73.97, 70.72,
69.91 (d, J=5.8), 54.20 (2, d, J=6.1), 52.41, 52.10, 44.50, 44.09,
37.43, 37.38, 36.66, 36.58, 35.36 (d, J=7.9), 34.48, 34.40, 30.57,
30.50, 30.21, 29.57, 26.05, 25.98, 24.85, 24.78, 24.74, 24.67,
20.23, 20.09, 13.20, 12.64; .sup.31P NMR (162 MHz, CDCl.sub.3)
.delta. 2.10; HRMS (El, m/z) for C.sub.36H.sub.59O.sub.12PNa
requires 737.3636, found 737.3646; IR (film, cm.sup.-1) 2955 (m),
2882 (w), 1722 (w), 1452 (w), 1380 (w), 1281 (w), 1189 (w), 1109
(m), 1037 (s), 1004 (s), 879 (w), 846 (w); [.alpha.]D.sup.23.7
71.0 (CHCl.sub.3, c=0.25).
Example 31
Synthesis of bis-trioxane primary
alcohol p-trifluoromethylbenzoate 28
To a stirring solution of bis-trioxane primary alcohol 4 (47.1 mg,
0.078 mmol) and .alpha.,.alpha.,.alpha.-trifluoro-p-toluic acid
(46.0 mg, 0.242 mmol) in anhydrous methylene chloride (1 mL) was
added 4-(dimethylamino)-pyridine (33.5 mg, 0.274 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(52.8 mg, 0.275 mmol). A further 2 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 3 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a white solid (101.5 mg). Gradient column
chromatography on silica (crude was dry-loaded) eluting with 10%
and then 20% ethyl acetate/petroleum ether isolated bis-trioxane
primary alcohol p-trifluoromethylbenzoate 28 as a colorless oil
(43.7 mg, 0.056 mmol, 72%). .sup.1H NMR (CDCl.sub.3, 400 MHz)
.delta. 8.16 (d, 2H, J=7.9), 7.70 (d, 2H, J=7.9), 5.32 (s, 1H),
5.27 (s, 1H), 4.60-4.42 (m, 3H), 4.37-4.29 (m, 1H), 2.70 (st, 1H,
J=7.0), 2.59 (st, 1H, J=7.0), 2.47-2.36 (m, 1H), 2.30 (td, 2H,
J=14.0, J=3.5), 2.06-1.72 (m, 8H), 1.69-1.49 (m, 6H), 1.43-1.13
(m, 14H, including two singlets at 1.40 and 1.39), 0.98-0.84 (m,
14H, including two doublets at 0.95 and 0.91 (J=5.8) and two
doublets at 0.87 and 0.86 (J=7.7)); .sup.13C NMR (CDCl.sub.3, 100
MHz) .delta. 165.22, 134.15 (d, J=34.5), 133.99, 129.89 (2),
125.29 (2, d, J=3.7), 123.64 (d, J=271.6), 103.14, 102.85, 89.46,
88.76, 81.09, 81.07, 73.23, 70.98, 67.87, 52.30, 52.08, 44.34,
44.09, 37.43 (2), 36.63, 36.53, 34.41, 34.39, 33.93, 30.56, 30.45,
30.09 (2), 26.05, 25.99, 24.95, 24.87, 24.73, 24.61, 20.08, 20.06,
14.09, 12.73; HRMS (El, m/z) for C.sub.42H.sub.57F.sub.3O.sub.10Na
requires 801.3796, found 801.3847; IR (film, cm.sup.-1) 2941,
2878, 1725, 1375, 1323, 1275, 1167, 1133, 1098, 1058, 1014, 661;
[.alpha.].sub.D.sup.243 58.2 (CHCl.sub.3, c=0.265).
Example 32
Synthesis of bis-trioxane primary
alcohol 3,5-ditrifluoromethyl benzoate 29
To a stirring solution of bis-trioxane primary alcohol 4 (48.9 mg,
0.081 mmol) and 3,5-bis(trifluoromethyl)benzoic acid (65.5 mg,
0.254 mmol) in anhydrous methylene chloride (2 mL) was added
4-(dimethylamino)-pyridine (36.0 mg, 0.295 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(55.1 mg, 0.287 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 15 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a bubbly white solid. Gradient column chromatography
on silica (crude was dry-loaded) eluting with 5%, 10% and then 20%
ethyl acetate/petroleum ether isolated bis-trioxane primary
alcohol 3,5-ditrifluoromethylbenzoate 29 as a colorless oil (64.7
mg, 0.076 mmol, 95%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta.
8.47 (s, 2H), 8.05 (s, 1H), 5.30 (s, 1H), 5.23 (s, 1H), 4.64-4.56
(m, 2H), 4.47 (dd, 1H, J=10.1, J=6.2), 4.32 (dd, 1H, J=10.1,
J=6.2), 2.69 (st, 1H, J=6.9), 2.59 (st, 1H, J=6.9), 2.45-2.35 (m,
1H), 2.35-2.24 (m, 2H), 2.05-1.51 (m, 14H), 1.42-1.13 (m, 14H,
including two singlets at 1.40 and 1.37), 0.98-0.85 (m, 14H,
including two doublets at 0.94 and 0.91 (J=5.5) and a broad
doublet at 0.87 (J=7.3)); .sup.13C NMR (CDCl.sub.3, 100 MHz)
.delta. 163.79, 133.08, 131.98 (2, d, J=34.0), 129.57 (2, d,
J=3.0), 125.94, 122.89 (2, d, J=275.2), 103.12, 102.86, 89.45,
88.77, 81.08, 81.04, 73.31, 70.82, 68.30, 52.24, 52.04, 44.31,
44.03, 37.46 (2), 36.58, 36.47, 34.35 (2), 34.22, 30.57, 30.48,
30.21, 29.98, 25.95, 25.96, 24.92, 24.86, 24.69, 24.53, 20.06,
20.04, 13.04, 12.65; HRMS (El, m/z) for
C.sub.43H.sub.56F.sub.6O.sub.10Na requires 869.3670, found
869.3680; [.alpha.].sub.d.sup.23.4 46.8 (CHCl.sub.3, c=0.305).
Example 33
Synthesis of bis-trioxane primary
alchohol dimethylglycinate 30
To a solution of bis-trioxane primary alcohol 4 (29.2 mg, 0.048
mmol) and N,N-dimethylglycine hydrochloride (22.1 mg, 0.158 mmol)
in anhydrous methylene chloride (1 mL) was added
4-(dimethylamino)-pyridine (22.8 mg, 0.187 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(36.2 mg, 0.189 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 15 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), saturated sodium bicarbonate solution (5 mL) and methylene
chloride (5 mL) were added and organics were extracted with
methylene chloride (3.times.20 mL), dried (Na.sub.2SO.sub.4) and
concentrated in vacuo to give an off-white solid. Gradient column
chromatography on silica eluting with 60%, 70% and then 80% ethyl
acetate/petroleum ether isolated bis-trioxane primary alcohol
dimethylgylcinate 30 as a colorless oil. Treatment with methylene
chloride (2.times.10 mL) and then hexanes (2.times.10 mL)
(followed by drying overnight under high vacuum) gave a white oily
solid (23.4 mg, 0.034 mmol, 70%). .sup.1H NMR (CDCl.sub.3, 400
MHz) .delta. 5.30 (s, br, 1H), 5.29 (s, br, 1H), 4.41-4.22 (m,
4H), 3.28 (s, 2H), 2.68 (st, 1H, J=6.8), 2.57 (st, 1H, J=6.8),
2.44 (s, 6H), 2.37-2.15 (m, 3H), 2.06-1.96 (m, 2H), 1.95-1.85 (m,
2H), 1.83-1.54 (m, 7H), 1.53-1.19 (m, 17H, including singlet at
1.39), 1.00-0.81 (m, 14H, including two doublets at 0.96 and 0.95
(J=5.8) and apparent triplet at 0.85 (J=6.9)); .sup.13C NMR
(CDCl.sub.3,100 MHz) .delta. 169.83, 103.18, 102.87, 89.42, 88.80,
81.13, 81.10, 73.47, 71.11, 66.97, 59.52, 52.35, 52.10, 44.72
(2),44.41, 44.11, 37.45, 37.42, 34.45, 34.40, 34.01, 30.55, 30.48,
29.97 (2), 26.08, 25.99, 24.82 (2), 24.74, 24.70, 20.20, 20.10,
13.12, 12.73; HRMS (El, m/z) for C.sub.38H.sub.61NO.sub.10Na
requires 714.4188, found 714.4236; IR (film, cm.sup.-1) 2944,
2873, 1738, 1452, 1373, 1195, 1105, 1048, 1005, 933, 877;
[.alpha.].sub.D.sup.23.8 71.3 (CHCl.sub.3, c=0.29).
Example 34
Synthesis of dihydroartemisinin
31
To a solution of artemisinin 1 (0.44 g, 1.55 mmol) in methanol (30
mL) at 0.degree. C. was added sodium borohydride (0.47 g, 12.3
mmol) in 4 portions, each at 15 minutes intervals. After addition
of the last portion, stirring was continued for 1 hour, at which
time TLC analysis confirmed no starting material remained.
Concentrated acetic acid was added dropwise until a pH of .about.5
was achieved and the resulting mixture was then concentrated in
vacuo to give a white solid. Water (30 mL) and methylene chloride
(30 mL) were added and organics were extracted with methylene
chloride (3.times.30 mL). The combined organic extracts were
washed with saturated sodium bicarbonate solution (20 mL), dried
(Na.sub.2SO.sub.4) and concentrated in vacuo to give a white solid
(0.46 g). Gradient column chromatography on silica (crude was
dry-loaded) eluting with 40% then 50% diethyl ether/petroleum
ether isolated dihydroartemisinin 31 as a white solid (0.38 g,
1.33 mmol, 86%, isolated as a 1.0:0.9 mixture of
.beta.:.alpha.-dihydroartemisinin). .sup.1H NMR (CDCl.sub.3, 400
MHz) .delta. 5.61 (s, 1H), 5.40 (s, 0.9H), 5.31 (d, 1H, J=3.4),
4.76 (d, 0.9H, J=9.2) [only characetistic peaks listed].
Example 35
Synthesis of
.alpha.-dihydroartemisinin dimethylglycinate 32
To a solution of dihydroartemisinin 31 (25.1 mg, 0.088 mmol) and
N,N-dimethylglycine hydrochloride (32.9 mg, 0.236 mmol) in
anhydrous methylene chloride (2 mL) was added
4-(dimethylamino)-pyridine (36.5 mg, 0.299 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(55.8 mg, 0.291 mmol). A further 0.5 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 3 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), saturated sodium bicarbonate solution (5 mL) and methylene
chloride (5 mL) were added and organics were extracted with
methylene chloride (3.times.20 mL), dried (Na.sub.2SO.sub.4) and
concentrated in vacuo to give an off-white solid (81.5 mg). Flash
column chromatography on silica (crude was dry-loaded) eluting
with 100% ethyl acetate isolated .alpha.-dihydroartemisinin
dimethylglycinate 32 as a colorless oil (31.5 mg, 0.085 mmol,
97%). .sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 5.85 (d, 1H,
J=9.9), 5.43 (s, 1H), 3.26 (AB, 2H, J=26.5, J=17.2), 2.61-2.50 (m,
1H), 2.36 (s, 6H), 2.41-2.32 (m, 1H), 2.02 (d, br,1H, J=14.4),
1.93-1.84 (m, 1H), 1.81-1.68 (m, 2H), 1.62 (dt, 1H, J=13.8,
J=4.4), 1.50-1.39 (m, 4H, including singlet at 1.42), 1.38-1.22
(m, 3H), 1.07-0.95 (m, 1H), 0.95 (d, 3H, J=5.9), 0.84 (d, 3H,
J=7.1); .sup.13C NMR (CDCl.sub.3, 100 MHz) .delta. 169.38, 104.42,
91.86, 91.48, 80.05, 59.95, 51.51, 45.20, 45.17 (2), 37.23, 36.16,
34.03, 31.80, 25.89, 24.53, 21.96, 20.18, 12.08; HRMS (El, m/z)
for C.sub.19H.sub.31NO.sub.6Na requires 392.2044, found 392.2021;
IR (film, cm.sup.-1) 2931, 2861, 2766, 1758, 1452, 1376, 1278,
1226, 1190, 1149, 1130, 1098, 1035, 1014, 926, 874, 846.
Example 36
Synthesis of
.alpha.-dihydroartemisinin isonicotinate N-oxide 33
To a stirring suspension of dihydroartemisinin 31 (33.6 mg, 0.12
mmol) and isonicotinic acid N-oxide (51.7 mg, 0.37 mmol) in
anhydrous methylene chloride (1 mL) was added
4-(dimethylamino)-pyridine (52.0 mg, 0.43 mmol) and
1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride
(81.7 mg, 0.43 mmol). A further 1 mL of anhydrous methylene
chloride was added to wash down the flask walls and the reaction
was stirred at room temperature for 4 hours, at which time TLC
analysis showed full consumption of starting material. Water (5
mL), 3M HCl solution (5 mL) and methylene chloride (5 mL) were
added and organics were extracted with methylene chloride
(3.times.20 mL), dried (Na.sub.2SO.sub.4) and concentrated in
vacuo to give a yellow tinged colorless oil (76.7 mg). Gradient
column chromatography on silica (crude was dry-loaded) eluting
with 60%, 80%, 90% and then 95% ethyl acetate/petroleum ether
isolated a-dihydroartemisinin isonicotinate N-oxide 33 as a
colorless oil. Treatment with methylene chloride (2.times.10 mL)
and then hexanes (2.times.10 mL) (followed by drying overnight
under high vacuum) gave a white solid (42.2 mg, 0.10 mmol, 88%).
.sup.1H NMR (CDCl.sub.3, 400 MHz) .delta. 8.22 (d, 2H, J=7.3),
7.95 (d, 2H, J=7.3), 5.95 (d, 1H, J=9.9), 5.51 (s, 1H), 2.78-2.67
(m, 1H), 2.38 (dt, 1H, J=13.5, J=3.9), 2.08-2.00 (m, 1H),
1.95-1.64 (m, 4H), 1.55-1.22 (m, 7H, including singlet at 1.41),
1.09-0.84 (m, 7H, including doublet at 0.97 (J=5.9) and doublet at
0.91 (J=7.1); .sup.13C NMR (CDCl.sub.3, 100 MHz) .delta. 162.11,
139.42 (2), 126.77 (2), 125.82, 104.50, 93.33, 91.60, 80.00,
51.47, 45.15, 37.21, 36.11, 33.96, 31.77, 25.83, 24.48, 21.94,
20.15, 12.16; HRMS (El, m/z) for C.sub.21H.sub.27NO.sub.7Na
requires 428.1680, found 428.1674; IR (film, cm.sup.-1) 2925,
2872, 2359, 2343, 1733, 1612, 1486, 1444, 1262, 1165, 1132, 1091,
1053, 1036, 1016, 872, 855, 827, 768; Mp. 118-122.degree. C.
(morphological change observed beginning at 90.degree. C.);
[.alpha.].sub.D.sup.24.7 4.67 (CHCl.sub.3, c=0.465); Anal
(C.sub.21H.sub.27NO.sub.7) C, H, N.
Example 37
Synthesis of bis-trioxane allyl
tertiary alcohol 34
A solution of bis-trioxane ketone 7 (20.0 mg, 0.034 mmol) in
anhydrous tetrahydrofuran (1.5 mL) was cooled to -78.degree. C.
before addition of allyl magnesium bromide (1.0 M solution in
diethyl ether, 0.140 mL, 0.140 mmol). After stirring for one hour,
TLC analysis confirmed that no starting material remained. The
reaction was quenched with 1.0 mL distilled water. The reaction
mixture was poured into a mixture of brine (20 mL) and diethyl
ether (30 mL) and the organic layer was separated, dried
(Na.sub.2SO.sub.4) and concentrated in vacuo to give a yellow oil.
Gradient column chromatography on silica eluting with 15 to 20%
ethyl acetate/hexanes isolated bis-trioxane allyl tertiary alcohol
34 as a foamy solid (20.6 mg, 0.033 mmol, 96%). .sup.1H NMR
(CDCl.sub.3, 400 MHz) .delta. 5.95-5.87 (m, 1H), 5.36 (s, 1H),
5.33 (s, 1H), 5.15 (apparent d, 1H, J=17.6), 5.09 (dd, 1H, J=10.4,
J=2.4), 4.80-4.63 (m, 1H), 4.60-4.54 (m, 1H), 2.70-2.41 (m, 4H),
2.34-2.27 (m, 2H), 1.40 (s, 1H), 1.39 (s, 3H), 0.95 (apparent d,
6H, J=5.6), 0.87 (apparent t, 6H, J=8.4); HRMS (ES, m/z) calcd for
C.sub.36H.sub.56O.sub.9Na (M+Na) 655.3817, found 655.3771.
Example 38
Synthesis of bis-trioxane
tertiary alcohol carboxylic acid 35
To a solution of bis-trioxane allyl tertiary alcohol 34 (20.6 mg,
0.033 mmol) in ethyl acetate (0.6 mL), acetonitrile (0.6 mL) and
H.sub.2O (0.2 mL) was added ruthenium(III) chloride hydrate (1.3
mg, 0.007 mmol) and sodium periodate (27.8 mg, 0.13 mmol) (on
addition of ruthenium chloride the solution turned black). After
stirring for 30 mins at room temperature (during which time the
color of the solution changed to pale orange), the reaction
mixture was poured into a mixture of ethyl acetate (30 mL) and
saturated aqueous NH.sub.4Cl solution (30 mL). Organics were
extracted with ethyl acetate (2.times.30 mL), dried (MgSO.sub.4),
filtered through a pad of celite and concentrated in vacuo. Flash
column chromatography on silica eluting with 1% acetic acid in 35%
ethyl acetate/hexane isolated bis-trioxane tertiary alcohol
carboxylic acid 35 as a white solid (16.7 mg, 0.026 mmol, 79%).
Mp=108-110.degree. C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.35 (s, 1H), 5.34 (s, 1H), 4.75-4.68 (m, 1H), 4.65-4.59 (m, 1H),
2.90 (ABq, 2H, J.sub.AB=15.6, .DELTA..nu..sub.AB=39.6), 2.61-2.48
(m, 2H), 2.36-2.25 (m, 2H), 2.05-1.60 (m, 15H), 1.46-1.20 (m, 15H,
including two siglets at 1.40 and 1.38), 0.98-0.82 (m, 2H), 0.96
(apparent doublet, 6H, J=5.2), 0.87 (apparent triplet, 6H, J=7.2);
.sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 103.01, 102.81, 89.87,
89.59, 81.11, 81.04, 74.26, 70.65, 70.03, 51.91, 44.13, 43.57,
38.91, 37.48, 37.43, 36.54, 36.47, 34.28, 30.91, 30.76, 25.92,
24.88, 24.75, 20.06, 12.38, 12.20; HRMS(ES) m/z calcd for
C.sub.35H.sub.54O.sub.11Na (M+Na) 673.3558, found 673.3510.
Example 39
Synthesis of bis-trioxane primary
alcohol methyl carbonate 36
To a solution of bis-trioxane primary alcohol 4 (26.5 mg, 0.044
mmol) in anhydrous pyridine (1.5 mL) at -20.degree. C. was added
methyl chloroformate (0.017 mL, 0.022 mmol). The reaction was
allowed to warm to room temperature and was stirred overnight
before being quenched with distilled water (1.0 mL). The reaction
mixture was then poured into a mixture of methylene chloride (20
mL) and saturated aqueous NH.sub.4Cl solution (20 mL). Organics
were extracted with methylene chloride (3.times.20 mL), dried
(MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 20% ethyl acetate/hexanes
isolated bis-trioxane primary alcohol methyl carbonate 36 as a
sticky solid (6.4 mg, 0.010 mmol, 22%). [.alpha.].sub.D.sup.23.2
64.2 (CHCl.sub.3, c=0.17); .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 5.30 (apparent s, 2H), 4.41-4.36 (m, 1H), 4.33 (apparent
doublet, 2H, J=4.8), 4.28-4.23 (m, 1H), 2.72-2.55 (m, 2H),
2.38-2.15 (m, 3H), 2.04-1.96 (m, 2H), 1.95-1.81 (m, 2H), 1.80-1.18
(m, 27H, including three singlets at 1.58, 1.40, 1.39), 0.97-0.80
(m, 2H), 0.95 (apparent d, 6H, J=6.0), 0.86 (d, 3H, J=7.6), 0.84
(d, 3H, J=7.2); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 155.79,
103.13, 102.83, 89.47, 88.86, 81.16, 81.15, 77.20, 73.60, 71.02,
70.05, 54.56, 52.38, 52.11, 44.45, 44.14, 37.42, 37.40, 36.67,
36.61, 34.48, 34.43, 34.22, 30.54, 30.49, 29.76, 26.09, 26.00,
24.83, 24.76, 24.70, 20.22, 20.11, 13.13, 12.69; IR (film,
cm.sup.-1) 2952, 2876, 1748, 1443, 1377, 1270, 1105, 1039, 1008,
928, 732; HRMS(ES) m/z calcd for C.sub.36H.sub.56O.sub.11Na (M+Na)
687.3715, found 687.3728.
Example 40
Synthesis of bis-trioxane primary
alcohol ethyl cabonate 37
To a solution of bis-trioxane primary alcohol 4 (15.5 mg, 0.026
mmol) in anhydrous pyridine (1.5 mL) at 0.degree. C. was added
ethyl chloroformate (large excess, .about.10.0 equiv). The
reaction was allowed to warm to room temperature and was stirred
overnight, before being quenched with distilled water (1.0 mL).
The reaction mixture was then poured into a mixture of methylene
chloride (20 mL) and saturated aqueous NH.sub.4Cl solution (20
mL). Organics were extracted with methylene chloride (3.times.20
mL), dried (MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 20% ethyl acetate/hexane
isolated bis-trioxane primary alcohol ethyl carbonate 37 as a
sticky solid (8.5 mg, 0.013 mmol, 49%). [.alpha.].sub.D.sup.23.7
75.9 (CHCl.sub.3, c=0.23); .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 5.30 (apparent s, 2H), 4.41-4.35 (m, 1H), 4.32 (apparent
d, 2H, J=4.8), 4.28-4.22 (m, 1H), 4.17 (q, 2H, J=6.8), 2.73-2.55
(m, 2H), 2.38-2.15 (m, 3H), 2.04-1.96 (m, 2H), 1.96-1.18 (m, 29H,
including a singlet at 1.39 and a triplet at 1.30 (J=7.2)),
0.97-0.80 (m, 2H), 0.95 (apparent d, 6H, J=5.6), 0.85 (apparent t,
6H, J=7.2); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta. 155.23,
163.13, 102.84, 89.43, 88.80, 81.15, 81.13, 73.72, 71.13, 69.80,
63.67, 52.39, 52.13, 44.48, 44.16, 37.42, 37.39, 36.67, 36.61,
34.50, 34.44, 34.26, 30.53, 30.42, 29.73, 26.10, 26.09, 24.83,
24.76, 24.70, 20.21, 20.12, 14.31, 13.17, 12.71; IR (film,
cm.sup.-1) 2939, 2872, 1744, 1453, 1377, 1260, 1105, 1038, 1008,
928, 880, 792; HRMS(ES) m/z calcd for C.sub.37H.sub.58O.sub.11Na
(M+Na) 701.3873, found 701.3919.
Example 41
Synthesis of bis-trioxane
tertiary alcohol methyl sulfonate 38
To a solution of methyl methanesulfonate (0.027 mL, 0.32 mmol) in
anhydrous tetrahydrofuran (1.5 mL) at -78.degree. C. was added
n-butyl lithium (1.3 M sol. in hexanes, 0.26 mL, 0.35 mmol). The
reaction was stirred at -78.degree. C. for 30 mins before slow
addition of a solution of bis-trioxane ketone 7 (37.6 mg, 0.064
mmol) in anhydrous tetrahydrofuran (0.8 mL). After stirring for 30
min., the reaction was quenched with distilled water (1.0 mL) and
the reaction mixture was poured into a mixture of diethyl ether
(20 mL) and saturated aqueous NH.sub.4Cl solution (20 mL). The
organic layer was then separated, dried (MgSO.sub.4) and
concentrated in vacuo. Flash column chromatography on nsilica
eluting with 30% ethyl acetate/hexanes isolated bis-trioxane
tertiary alcohol methyl sulfonate 38 as a white solid (42.0 mg,
0.060 mmol, 94%). Mp=87-90.degree. C.; .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 5.44 (s, 1H), 5.36 (s, 1H), 4.85-4.79 (m, 1H),
4.71-4.65 (m, 2H), 3.81 (ABq, 2H, J.sub.AB=14.4,
.DELTA..nu..sub.AB=142.4), 3.96 (s, 3H), 2.76-2.67 (m, 1H),
2.59-2.91 (m, 1H), 2.38-2.15 (m, 3H), 2.06-1.82 (m, 6H), 1.81-1.19
(m, 21H, including two singlets at 1.40 and 1.37), 0.97-0.80 (m,
2H), 0.96 (d, 3H, J=5.6), 0.95 (d, 3H, J=6.0), 0.89 (d, 3H,
J=7.2), 0.88 (d, 3H, J=7.2 Hz); .sup.13C NMR (100 MHz, CDCI.sub.3)
.delta. 103.17, 102.81, 89.97, 88.96, 81.12, 72.84, 70.74, 70.28,
56.60, 55.69, 52.25, 51.84, 44.27, 43.37, 39.02, 37.48, 37.39,
36.62, 36.49, 34.27, 30.74, 30.56, 25.96, 25.92, 24.91, 24.77,
24.54, 20.15, 20.12, 13.04, 12.00; IR (film, cm.sup.-1) 3469,
2951, 2875, 1451, 1377, 1356, 1175, 1099, 1053, 1007, 911, 879,
731; HRMS(ES) m/z calcd for C.sub.35H.sub.56O.sub.12SNa (M+Na)
723.3385, found 723.3397.
Example 42
Synthesis of bis-trioxane
tertiary alcohol isopropyl sulfonate 39
To a solution of isopropyl methanesulfonate (0.009 mL, 0.066 mmol)
in anhydrous tetrahydrofuran (1.0 mL) at -78.degree. C. was added
n-butyl lithium (1.3 M sol. in hexanes, 0.055 mL, 0.073 mmol). The
reaction was stirred at -78.degree. C. for 30 mins before slow
addition of a solution of bis-trioxane ketone 7 (7.8 mg, 0.013
mmol) in anhydrous tetrahydrofuran (0.4 mL). After stirring for a
further 30 mins, the reaction was quenched with distilled water
(1.0 mL) and the reaction mixture was poured into a mixture of
diethyl ether (20 mL) and saturated aqueous NH.sub.4Cl solution
(20 mL). The organic layer was then separated, dried (MgSO.sub.4)
and concentrated in vacuo. Flash column chromatography on silica
eluting with 20% ethyl acetate/hexanes to afford bis-trioxane
tertiary alcohol isopropyl sulfonate 39 as a sticky solid (5.8 mg,
0.008 mmol, 60%). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 5.46
(s, 1H), 5.36 (s, 1H), 5.11 (st, 1H, J=6.4), 4.88-4.84 (m, 1H),
4.67-4.63 (m, 2H), 3.78 (ABq, 2H, J.sub.AB=14.0,
.DELTA..nu..sub.AB=146.8), 1.43 (s, 3H), 1.41 (s, 3H), 0.96 (d,
3H, J=6.0), 0.94 (d, 3H, J=6.0), 0.88(d, 3H, J=7.2), 0.87 (d, 3H,
J=7.2); HRMS(ES) m/z calcd for C.sub.37H.sub.60O.sub.12SNa (M+Na)
751.3698, found 751.3749.
Example 43
Synthesis of bis-trioxane
tertiary alcohol N,N-dimethylsulfonamide 40
To a solution of N,N-dimethyl methanesulfonamide (10.8 mg, 0.088
mmol) in anhydrous tetrahydrofuran (1.5 mL) at -78.degree. C. was
added n-butyl lithium (1.3 M sol. in hexanes, 0.072 mL, 0.097
mmol). The reaction was stirred at -78.degree. C. for 30 mins
before slow addition of a solution of bis-trioxane ketone 7 (10.4
mg, 0.018 mmol) in anhydrous tetrahydrofuran (0.5 mL). After
stirring for a further 30 mins, the reaction was quenched with
distilled water (1.0 mL) and the reaction mixture was poured into
a mixture of diethyl ether (20 mL) and saturated aqueous
NH.sub.4Cl solution (20 mL). The organic layer was then separated,
dried (MgSO.sub.4) and concentrated in vacuo. Gradient column
chromatography on silica eluting with 25% and then 30% ethyl
acetate/hexanes isolated bis-trioxane tertiary alcohol
N,N-dimethylsulfonamide 40 as a white solid (7.9 mg, 0.011 mmol,
63%). Mp=107-110.degree. C.; [.alpha.].sub.D.sup.245 74.7
(CHCl.sub.3, c=0.25); .sup.1H NMR (400 MHz, CDCl.sub.3) .delta.
5.50 (s, 1H), 5.37 (s, 1H), 5.01-4.95 (m, 1H), 4.63-4.59 (s, 1H),
4.61 (m, 1H), 3.56 (ABq, 2H, J.sub.AB=13.6,
.DELTA..nu..sub.AB=207.2), 2.90 (s, 6H), 2.86-2.78 (m, 1H),
2.66-2.57 (m, 1H), 2.44-2.27 (m, 3H), 2.08-1.88 (m, 4H), 1.87-1.19
(m, 23H, including two singlets at 1.39 and 1.34), 0.97-0.80 (m,
2H), 0.95 (d, 3H, J=8.0), 0.94 (d, 3H, J=8.4 Hz), 0.88 (apparent
triplet, 6H, J =7.2); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.
103.38, 102.82, 89.87, 88.33, 81.27, 81.22, 72.80, 71.50, 71.10,
52.51, 51.93, 51.13, 44.86, 43.42, 39.22, 37.85, 37.50, 37.30,
37.00, 36.48, 34.51, 34.32, 30.58, 30.51, 26.04, 25.99, 24.98,
24.77, 24.60, 24.36, 20.24, 20.05, 13.61, 11.94; IR (film,
cm.sup.-1) 3470, 2938, 2875, 1453, 1377, 1330, 1197, 1151, 1099,
1052, 1009, 955, 878, 734, 709; HRMS(ES) m/z calcd for
C.sub.36H.sub.59NO.sub.11SNa (M+Na) 736.3701, found 736.3660.
Example 44
Synthesis of bis-trioxane vicinal
diol cyclic carbonate 41
To a solution of bis-trioxane vicinal diol 5 (5.8 mg, 0.009 mmol)
in methylene chloride (1.0 mL) was added 1,1'-carbonyl diimidazole
(4.5 mg, 0.028 mmol) and 4-(dimethylamino)-pyridine (3.4 mg, 0.028
mmol). The mixture was then stirred at room temperature overnight.
The reaction was poured into a mixture of methylene chloride (20
mL) and saturated aqueous NH.sub.4Cl solution (20 mL) and the
organic layer was separated. The organics were then washed with
brine, dried (MgSO.sub.4) and concentrated in vacuo. Flash column
chromatography on silica eluting with 25% ethyl acetate/hexanes
isolated bis-trioxane vicinal diol cyclic carbonate 41 as a white
solid (5.8 mg, 0.009 mmol, 96%). .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 5.31 (s, 1H), 5.30 (s, 1H), 4.84 (d, 1H, J=8.8), 4.67 (dd,
1H, J=6.4, J=1.6), 4.62 (dd, 1H, J=6.4, J=1.6), 4.45 (d, 1H,
J=8.8), 2.65-2.48 (m, 2H), 2.35-2.25 (m, 2H), 2.38-1.58 (m, 14H),
1.46-1.18 (m, 20H, including two singlets at 1.40 and 1.37), 0.95
(d, 6H, J=5.6), 0.88 (d, 3H, J=7.6), 0.86 (d, 3H, J=7.6),
0.98-0.86 (m, 2H); .sup.13C NMR (100 MHz, CDCl.sub.3) .delta.
154.9, 102.8, 102.8, 89.9, 89.6, 85.4, 81.0, 80.8, 72.2, 68.9,
68.0, 51.8, 51.8, 43.7, 43.5, 39.0, 37.5, 37.4, 36.7, 36.6, 35.6,
34.3, 34.2, 30.8, 30.7, 25.9, 25.7, 24.8, 24.7, 20.0, 12.4, 12.3;
HRMS(ES) m/z calcd for C.sub.35H.sub.52O.sub.11Na (M+Na) 671.3407,
found 671.3412.
Example 45
Synthesis of bis-trioxane vicinal
diol cyclic sulfate 42
To a solution of bis-trioxane vicinal diol 5 (18.0 mg, 0.029 mmol)
in anhydrous methylene chloride (2.0 mL) at 0.degree. C. was added
thionyl chloride (0.021 mL, 0.29 mmol) and triethylamine (0.064
mL, 0.46 mmol) (on addition of triethylamine the solution turned
light yellow). The reaction was stirred for one hour, at which
time TLC analysis showed complete consumption of starting
material. The reaction was quenched with distilled water (1.0 mL)
and was poured into a mixture of methylene chloride (20 mL) and
saturated aqueous NH.sub.4Cl solution (20 mL). The organic layer
was then separated, dried (MgSO.sub.4) and concentrated in vacuo
to give a yellow oil. A 10 mL round-bottomed flask was charged
with the crude material, followed by the addition of ethyl acetate
(0.7 mL), and then acetonitrile (0.7 mL) and water (0.3 mL).
Ruthenium (III) chloride hydrate (1.2 mg, 0.006 mmol, 0.2
equiv--based on 5) and sodium periodate (24.8 mg, 0.116 mmol, 4.0
equiv--based on 5) were added (on addition of ruthenium chloride
the solution turned black). After stirring for 30 mins at room
temperature (the color of the solution changed to pale orange),
the reaction mixture was poured into a mixture of ethyl acetate
(30 mL) and saturated aqueous NH.sub.4Cl solution (30 mL). The
aqueous layer was extracted with ethyl acetate (2.times.30 mL),
and the combined organics were dried (MgSO.sub.4), filtered
through a pad of celite and concentrated in vacuo. Gradient column
chromatography on silica eluting with 10%, 15% and then 20% ethyl
acetate/hexanes isolated bis-trioxane vicinal diol cyclic sulfate
42 as a white solid (17.1 mg, 0.026 mmol, 86%). Mp=107-110.degree.
C.; .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 5.37 (s, 1H), 5.30
(s, 1H), 4.84 (ABq, 2H, J.sub.AB=9.6, .DELTA..nu..sub.AB=58.4),
4.61-4.55 (m, 2H), 2.75-2.66 (m, 1H), 2.60-2.48 (m, 2H), 2.36-2.20
(m, 4H), 2.07-1.85 (m, 6H), 1.82-1.56 (m, 8H), 1.42 (s, 3H),
1.37(s, 3H), 0.97-0.80 (m, 2H), 0.96 (apparent triplet, 6H, J
=6.0), 0.89 (d, 3H, J=7.6), 0.88 (d, 3H, J=7.2); .sup.13C NMR (100
MHz, CDCl.sub.3) .delta. 103.20, 102.68, 95.49, 89.83, 89.28,
81.16, 80.86, 77.32, 68.95, 68.87, 52.19, 51.76, 44.15, 43.30,
37.53, 37.30, 36.62, 36.54, 34.57, 34.45, 34.19, 30.75, 30.23,
29.69, 25.98, 25.86, 24.83, 24.76, 20.15, 19.99, 12.92, 12.05; IR
(film, cm.sup.-1) 2941, 2876, 1455, 1380, 1209, 1114, 1093, 1009,
978, 828, 731; HRMS(ES) m/z calcd for C.sub.34H.sub.52O.sub.12SNa
(M+Na) 707.3072, found 707.3087.
Example 46
Synthesis of bis-trioxane
tertiary alcohol pyridine sulfide 43
A 10 mL round-bottomed flask was charged with bis-trioxane epoxide
6 (8.2 mg, 0.013 mmol), 4-mercaptopyridine (15 mg, 0.13 mmol) and
neutral aluminum oxide (1.0 g, type W 200 super I, Woelm Pharma,
Germany). Anhydrous diethyl ether (0.9 mL) and methylene chloride
(0.6 mL) were then added to make a slurry and the reaction was
stirred at room temperature overnight. The reaction mixture was
then filtered through a pad of celite and the solid was washed
with ethyl acetate (2.times.30 mL) before concentration of the
organics in vacuo. Flash column chromatography on silica eluting
with 45% ethyl acetate/hexanes isolated bis-trioxane tertiary
alcohol pyridine sulfide 43 as a sticky solid (3.0 mg, 0.04 mmol,
31%). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.36-8.32 (m, 2H),
7.31-7.25 (m, 2H), 5.36 (s, 1H), 5.35 (s, 1H), 4.75-4.71 (m, 1H),
4.57-4.53 (m, 1H), 4.37 (s, 1H), 3.51 (ABq, 2H, J.sub.AB=12.8,
.DELTA..nu..sub.AB=34.0), 2.61-2.45 (m, 2H), 2.35-2.35(m, 2H),
2.09-1.87 (m, 6H), 1.80-1.60 (m, 10H), 1.40-1.18 (m, 12H,
including two singlets at 1.35 and 1.33), 0.98-0.86 (m, 2H), 0.96
(d, 6H, J=6.0), 0.88 (d, 3H, J=7.6), 0.85 (d, 3H, J=7.6); HRMS(ES)
m/z calcd for C.sub.39H.sub.57NO.sub.9SNa (M+Na) 738.3646, found
738.3664.
Example 47
Synthesis bis-trioxane ketone
O-TMS cyanohydrin 44
To a solution of trimethylsilyl cyanide (0.003 mL, 0.023 mmol) in
anhydrous tetrahydrofuran (0.8 mL) at room temperature was added
lithium tertiary butoxide (1.0 M sol. in tetrahydrofuran, 0.002
mL, 0.002 mmol). The reaction was stirred for 10 mins at room
temperature before slow addition of a solution of bis-trioxane
ketone 7 (9.0 mg, 0.015 mmol) in anhydrous tetrahydrofuran (0.4
mL). After stirring for 30 mins, the reaction was quenched with
distilled water (1.0 mL). The reaction mixture was then poured
into a mixture of diethyl ether (20 mL) and 10% aqueous
NaHCO.sub.3 solution (20 mL) before the organic layer was
separated, dried (MgSO.sub.4) and concentrated in vacuo. Gradient
column chromatography on silica eluting with 10% and then 15%
ethyl acetate/hexanes isolated bis-trioxane ketone O-TMS
cyanohdrin 44 as a sticky solid (9.8 mg, 0.014 mmol, 93%). .sup.1H
NMR (400 MHz, CDCl.sub.3) .delta. 5.41 (s, 1H), 5.37 (s, 1H),
4.65-4.61 (m, 1H), 4.54-4.50 (m, 1H), 2.85-2.75 (m, 2H), 2.46-2.25
(m, 5H), 1.41 (s, 3H), 1.36 (s, 3H), 0.94 (apparent triplet, 6H,
J=6.0), 0.89 (d, 3H, J=7.6),0.86 (d, 3H, J=7.6), 0.25 (s, 9H); 13C
NMR (100 MHz, CDCl.sub.3) .delta. 121.67, 103.40, 103.01, 88.14,
88.07, 80.92, 80.85, 72.73, 72.08, 70.25, 52.46, 44.68, 44.63,
38.81, 38.22, 37.23, 37.06, 36.66, 36.60, 34.51, 34.40, 30.58,
30.29, 30.23, 29.69, 26.11, 26.04, 24.56, 24.48, 24.38, 24.30,
20.24, 20.20, 13.59, 13.51, 1.31; HRMS(ES) m/z calcd for
C.sub.37H.sub.59NO.sub.9Na (M+Na) 712.3851, found 712.3863.
Example 48
Synthesis of bis-trioxane
tertiary alcohol nitrile 45
To a solution of acetonitrile (0.005 mL, 0.096 mmol) and anhydrous
tetrahydrofuran (0.8 mL) at -78.degree. C. was added LHMDS (1.0 M
sol. in THF, 0.096 mL, 0.096 mmol). The reaction was then stirred
for 30 mins at -78.degree. C. before slow addition of a solution
of bis-trioxane ketone 7 (9.5 mg, 0.016 mmol) in anhydrous
tetrahydrofuran (0.5 mL). After stirring for 30 mins, the reaction
was quenched with distilled water (1.0 mL). The reaction mixture
was then poured into a mixture of diethyl ether (20 mL) and
saturated aqueous NH.sub.4Cl solution (20 mL). The organic layer
was separated, dried (MgSO.sub.4) and concentrated in vacuo. Flash
column chromatography on silica eluting with 25% ethyl
acetate/hexanes isolated bis-trioxane tertiary alcohol nitrile 45
as a white solid (6.0 mg, 0.009 mmol, 59%)..sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 5.38 (s, 1H), 5.34 (s, 1H), 4.74-4.70 (m, 1H),
4.60-4.55 (m, 1H), 4.44 (s, 1H), 2.94 (ABq, 2H, J.sub.AB=16.8,
.DELTA..nu..sub.AB=83.2), 2.05-1.86 (m, 8H), 1.82-1.62 (m, 6H),
1.45-1.19 (m, 18H, including two apparent singlets at 1.39 and
1.38), 0.97-0.80 (m, 2H), 0.96 (d, 6H, J=6.0), 0.89 (d, 3H,
J=7.2), 0.88 (d, 3H, J=7.2); .sup.13C NMR (100 MHz, CDCl.sub.3)
.delta. 118.55, 102.94, 102.69, 90.09, 89.54, 81.13, 81.07, 72.93,
70.07, 69.65, 52.01, 51.81, 43.69, 43.30, 38.87, 37.48, 37.45,
37.06, 36.53, 34.31, 34.24, 30.87, 30.69, 29.14, 25.97, 24.88,
24.81, 24.76, 24.71, 20.06, 20.00, 12.51, 12.13; HRMS(ES) m/z
calcd for C.sub.35H.sub.53NO.sub.9Na (M+Na) 654.3613, found
654.3632.
Example 49
Synthesis of bis-trioxane methyl
enol ether 46
To a slurry of (methoxymethyl)triphenylphosphonium chloride (400
mg, 1.2 mmol) in anhydrous tetrahydrofuran (10 mL) at 0.degree. C.
was added lithium bis(trimethylsilyl)amide (1.0 M solution in
tetrahydrofuran, 1.3 mL, 1.3 mmol) resulting in a deep dark red
color. The reaction mixture was allowed to warm to room
temperature and was stirred for 30 minutes, before being cooled to
-78.degree. C. At this time, a solution of bis-trioxane ketone 7
(270 mg, 0.46 mmol) in anhydrous tetrahydrofuran (10 mL) was added
dropwise. A color change to pale orange was observed immediately.
The reaction was stirred at -78.degree. C. for 3 hours, at which
time complete consumption of starting material was observed by TLC
analysis. The reaction mixture was quenched with distilled water
(5 mL) and organics were extracted with methylene chloride
(3.times.30 mL), dried (MgSO.sub.4) and concentrated in vacuo to
give a pale yellow oil. Flash column chromatography on silica
eluting with 20% ethyl acetate/petroleum ether isolated
bis-trioxane methyl enol ether 46 as a white solid (220 mg, 0.35
mmol, 76%). .sup.1H NMR (CDCl.sub.3) .delta. 5.86 (s,1H), 5.45 (s,
1H), 5.42 (s,1H), 4.10-4.00 (m, 2H), 3.53 (s, 3H), 2.78-2.76 (m,
2H), 2.45-2.22 (m, 4H), 2.02-1.95 (m, 2H), 1.90-1.70 (m, 4H),
1.60-1.50 (m, 6H), 1.40-1.15 (m, 14H including a singlet at 1.39),
1.00-0.85 (m, 14H); HRMS (ES) m/z calcd for
C.sub.35H.sub.54O.sub.9Na (M+Na) 641.3660, found 641.3657.
Example 50
Synthesis of bis-trioxane
aldehyde 47
A 50 mL round bottom flask was charged with bis-trioxane methyl
enol ether 46 (190 mg, 0.31 mmol), formic acid (10 mL) and diethyl
ether (15 mL). The reaction was stirred at room temperature for 8
hours until complete consumption of starting material was observed
by TLC analysis. The reaction was then poured into a separatory
funnel containing saturated NaHCO.sub.3 (20 mL) and diethyl ether
(20 mL). Organics were extracted with diethyl ether (3.times.30
mL), dried (MgSO.sub.4) and concentrated in vacuo to give a pale
yellow oil. Flash column chromatography on silica eluting with 20%
ethyl acetate/petroleum ether isolated bis-trioxane aldehyde 47 as
a white solid (160 mg 0.27 mmol, 87%). .sup.1H NMR (400 MHz,
CDCl.sub.3) .delta. 9.85 (d, 1H, J=1.2 Hz), 5.24 (s, 1H), 5.21 (s,
1H), 4.35-4.26 (m, 2H), 2.84-2.80 (m, 1H), 2.70-2.50 (m, 2H),
2.38-2.22 (m, 2H), 2.19-2.09 (m, 2H), 2.02-1.96 (m, 4H), 1.90-1.70
(m, 4H), 1.62-1.58 (m, 6H), 1.40-1.15 (m, 12H, including two
singlets at 1.39 and 1.38), 0.98-0.82 (m, 14H); 13C NMR (100 MHz,
CDCl.sub.3) .delta. 205.6, 103.8, 103.1, 89.69, 89.15, 81.47,
81.43, 73.37, 70.94, 52.54, 52.58, 47.79, 44.48, 44.20, 37.72,
37.65, 36.85 (2), 34.70, 34.65, 30.68, 30.51, 29.97, 28.92, 26.30,
26.19, 25.13, 25.11, 25.02, 24.95, 20.43, 20.37, 13.30, 12.74;
HRMS (ES) m/z calcd for C.sub.34H.sub.52O.sub.9Na (M+Na) 627.3504,
found 627.3445; IR (film, cm.sup.-1) 3100, 2800, 2250, 1650, 1400,
1300, 850, 600; Mp. 66-70.degree. C.
Example 51
Synthesis of bis-trioxane aniline
48
A 10 mL round bottom flask was charged with bis-trioxane aldehyde
47 (25 mg, 0.041 mmol), tetrahydrofuran (1.5 mL), aniline (0.008
mL, 0.088 mmol) and finally sodium triacetoxy borohydride (18 mg,
0.086 mmol). The reaction was stirred at room temperature for 3
hours until complete consumption of starting material was observed
by TLC analysis. The reaction was quenched with saturated
NaHCO.sub.3 solution (1.0 mL) and organics were extracted with
diethyl ether (3.times.30 mL), dried (MgSO.sub.4) and concentrated
in vacuo to give a pale yellow oil. Flash column chromatography on
silica eluting with 15% ethyl acetate/petroleum ether isolated
bis-trioxane aniline 48 as a colorless oil (15 mg, 0.023 mmol,
56%). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.16-7.11 (m, 2H),
6.70-6.60 (m, 3H), 5.34 (s, 1H), 5.31 (s, 1H), 4.46-4.26 (m, 2H),
3.29-3.15 (m, 2H), 2.72-2.56 (m, 2H), 2.36-2.27 (m, 2H), 2.22-2.16
(m, 1H), 2.10-1.99 (m, 2H), 1.93-1.86 (m, 2H), 1.79-1.71 (m, 5H),
1.65-1.55 (m, 5H), 1.50-1.21 (m, 14H including two singlets at
1.41 and 1.38), 0.96-0.84 (m, 14H); .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 149.1, 129.1, 116.3, 112.7, 103.2, 103.0,
89.37, 88.91, 81.17 (2), 73.90, 71.47, 52.32, 52.16, 47.34, 44.39,
44.21, 37.42, 37.28, 36.61, 36.58, 34.81, 34.42, 31.50, 31.13,
30.70, 30.54, 26.11, 26.02, 24.83, 24.77, 24.73, 24.67, 20.16,
20.13, 13.15, 12.76; HRMS (ES) m/z calcd for
C.sub.40H.sub.59NO.sub.8Na (M+Na) 704.4133, found 704.4136.
Thus, the present invention encompasses methods of treating cancer
(including but not limited to leukemia, non-small cell lung
cancer, colon cancer, central nervous system cancer, melanoma
cancer, ovarian cancer, renal cancer, prostate cancer, and breast
cancer) which include the step of administering to a patient
suffering from cancer a compound or combination of compounds
recited in claims 1-83 of PCT/US2003/030612. as published in WO
2004/028476 A2, and incorporated herein by this reference. The
present invention further encompasses methods of treating malaria
which include the step of administering an effective amount of a
compound or combination of compounds recited in claims 1-83 of
PCT/US2003/030612, as published in WO 2004/028476 A2.