Synthesis and biological evaluation of some new A,B-ring modified steroidal D-lactones

Starting from the D-homo lactones of androst-4-en-3-one 3 and 4, prepared from 1 and 2, the new 17a homolactones 5-12, 14 and 15, were synthesized. The 4-hydroxy compounds 9 and 10 were obtained through the reaction of 4alpha,5alpha- (5 and 7) and 4beta,5beta- (6 and 8) epoxides with formic acid. The epoxides 5 and 6 were prepared from compound 3, and epoxides 7 and 8 from compound 4 by oxidation with H(2)O(2) under basic conditions. Compound 1 served as a starting substance for obtaining lactones 11-13. Oxidation of compound 1 with m-chloroperbenzoic acid yielded 11 and 12, but compound 13 gave 14. Compound 15 was obtained from 13 by oxidation with H(2)O(2) under basic conditions. The structures of epoxides 6 and 14 were confirmed by X-ray structural analysis. Cytotoxic activity against three tumor cell lines (human breast adenocarcinoma ER+, MCF-7, human breast adenocarcinoma ER-, MDA-MB-231, and prostate cancer PC3) was evaluated. Compounds 6 and 14 showed strong activity against PC3, the IC(50) being 10.6 and 2.2 microM, respectively, whereas compounds 3 and 8 showed strong activity against MDA-MB-231 (IC(50) is 9.3 and 3.6 microM, respectively). Aromatase inhibition assay showed that the tested compounds 9, 10, and 14 possess lower activity compared to formestane.     

Active nonaromatic intermediates in the conversion of steroidal estrogens into catechol estrogens

A mechanism is proposed for mixed-function oxidase-catalyzed formation of the catechol estrogens 2-hydroxy- and 4-hydroxyestradiol from estradiol. This mechanism involves nonaromatic epoxyenones as intermediates. The isomeric 1 alpha,2 alpha-epoxy-17 beta-hydroxyestr-4-en-3-one and 1 beta,2 beta-epoxy-17 beta-hydroxyestr-4-en-3-one (the latter as its 17-acetate) were synthesized from 17 beta-hydroxy-5 alpha-estran-3-one. The isomeric 4 alpha,5 alpha-epoxy-17 beta-hydroxyestr-1-en-3-one and 4 beta,5 beta-epoxy-17 beta-hydroxyestr-1-en-3-one were prepared from 19-nortestosterone. From incubations of [6,7-3H]estradiol with microsomes from MCF-7 human breast cancer cells, which principally catalyze the formation of 2-hydroxyestradiol from estradiol, we were able to isolate a 3H-labeled product with the chromatographic properties of 1 beta, 2 beta-epoxy-17 beta-hydroxyestr-4-en-3-one (as its 17-acetate). The soluble protein fraction of homogenates of rat liver, which is devoid of estrogen 2-/4-hydroxylase activity, has been shown to catalyze the formation of 2- and 4-hydroxyestradiol from the 1 alpha,2 alpha-epoxide and from the 4 alpha,5 alpha- and 4 beta,5 beta-epoxides, respectively. We suggest that these results taken together strongly support a role for epoxyenones as intermediates in the formation of catechol estrogens.     

Withanolides from Withania somnifera roots

Two new and seven known withanolides along with beta-sitosterol, stigmasterol, beta-sitosterol glucoside, stigmasterol glucoside, alpha+beta glucose were isolated from the roots of Withania somnifera. Among the known compounds, Viscosa lactone B, stigmasterol, stigmasterol glucoside and alpha+beta glucose are being reported from the roots of W. somnifera for the first time. One of the new compounds contained the rare 16beta-acetoxy-17(20)-ene the other contained unusual 6alpha-hydroxy-5,7alpha-epoxy functional groups in the withasteroid skeleton. The structures were elucidated by spectroscopic methods and chemical transformations.     

Synthesis of 5 beta,17 alpha-19-norpregn-20-yne-3 beta,17-diol and of 5 beta,17 alpha-19-norpregn-20-yne-3 alpha,17-diol, human metabolites of norethindrone

A convenient synthesis of both 5 beta,17 alpha-19-norpregn-20-yne-3 beta,17-diol (1) and 5 beta,17 alpha-19-norpregn-20-yne-3 alpha,17-diol (2) in multigram quantities from estr-4-ene-3,17-dione is reported. Full characterization of these often-cited human metabolites of norethindrone is presented for the first time.     

Reaction of thiol nucleophiles with 1,2-epoxy- and 4,5-epoxy-estrene-3-one-17 beta-ols

Four ring A steroidal epoxyenones as probable intermediate in the formation of catechol estrogens were synthesized. The isomeric 1 alpha,2 alpha-epoxy-17 beta-hydroxyestr-4-en-3-one (9) and 1 beta,2 beta-epoxy-17 beta-hydroxyestr-4-en-3-one (8) were synthesized from 17 beta-hydroxy-5 alpha-estra-3-one. The isomeric 4 alpha,5 alpha-epoxy-17 beta-hydroxyestr-1-en-3-one (11) and 4 beta,5 beta-epoxy-17 beta-hydroxyestr-1-en-3-one (10) were prepared from 19-nortestosterone. The reaction of 9 and 10 with sodium/ethanethiol resulted in the formation of three types of reactions leading to multiple products: 1,4-addition, opening of epoxide, and epoxide opening followed by dehydration. Reaction of 8 with ethanethiol gave only one compound identified as 2-ethanethio-1,4-estradien-17 beta-ol-3-one, while reaction of 9 with ethanethiol gave an unusual product identified as 4-estren-1 alpha,17 beta-diol-3-one. Unlike reaction of ethanethiol with 9 and 10, reaction with N-acetylecysteine or glutathione results in epoxide opening followed by dehydration leading to the formation of estradiol-4-thioethers.     

Oxidation of 17alpha,20beta- and 17alpha,20alpha-dihydroxysipregn-4-en-ones--side products of biotransformation of progesterone by recombinant microorganisms expressing cytochrome P45017alpha

Progesterone biotransformation with recombinant yeast Yarrowia lipolytica E129A15 and Saccharomyces cerevisiae GRF18/YEp5117 alpha expressing bovine adrenocortical cytochrome P45017 alpha yielded 17 alpha-hydroxyprogesterone and two diols, 17 alpha, 20 beta- and 17 alpha, 20 alpha-dihydroxypregn-4-en-3-one. The oxidation of mixtures of the three steroids with chromic acid resulted in the cleavage of 17-20 bonds in the diols with the formation of androst-4-ene-3,17-dione. The biotransformation of pregn-4-ene-20 beta-ol-3-one by means of Y. lipolytica E129A15 was accompanied by the following reactions: the primary oxidation of these compounds to progesterone and the subsequent successive reactions of 17 alpha-hydroxylation and 20 alpha- and 20 beta-reduction. The results widen the possibilities for enzymatic and chemical modifications of steroids. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2003, vol. 29, no. 6; see also http://www.maik.ru.     

Preparation of 3 beta, 5 alpha-, 3 alpha, 5 alpha- and 3 alpha, 5 beta-tetrahydro derivatives of 19-noraldosterone by chemical synthesis and microbial bioconversion

The 3 beta, 5 alpha-, 3 alpha, 5 alpha- and 3 alpha, 5 beta-tetrahydro derivatives 19, 20 and 27 of 19-noraldosterone (1) were prepared to facilitate the search for these compounds in urine. The diketal 4, consisting of a 2:1 mixture of the 5,6- and 5(10)-ene isomers, was hydrogenated with Pd-C and partially hydrolyzed to 5 alpha, 10 alpha- and 5 alpha, 10 beta-dihydroketals 8 and 10 in a 1:2.5 ratio. Assignment of protons was done with aid of COSY 45 experiments. Compound 10 was reduced with diisobutylaluminum hydride (DIBAH) to 4 products: the 3 alpha- and 3 beta-ol hemiacetals 16 and 15, and the corresponding tetraols 14 and 13. Alternatively, hydrogenation of the 4-en-3-one 2 gave 10, its 5 beta, 10 beta-isomer 21 and the tetrahydro compound 22, in a 4:2:1 ratio. A better way to prepare the 5 beta, 10 beta-series involved microbial conversion of 2 with Clostridium paraputrificum, and the resulting tetrahydrolactone 23 was reduced with DIBAH to the hemiacetal 24. Acid hydrolysis of 16, 15 and 24 afforded 20, 19 and 27, respectively. According to [1H]-NMR, in solution 20 and 24 exist as mixtures of isomers, while 19 appears in one form only. Periodate oxidation converted 19 and 27 into their gamma-etiolactones 18 and 28. EI MS base peaks are different and characteristic for 19, 20 and 27.     

21beta-Hydroxy-oleanane-type triterpenes from Hippocratea excelsa

Stem bark of Hippocratea excelsa afforded six pentacyclic triterpenes, five oleanane and one ursane types. They were identified as 11beta,21beta-dihydroxy-olean-12-ene-3-one (2), 3alpha,11alpha,21beta-trihydroxy-olean-12-ene (3), 3alpha,21beta-dihydroxy-11alpha-methoxy-olean-12-ene (4), 3alpha,21beta-dihydroxy-olean-9(11),12-diene (5), 3alpha,21beta-dihydroxy-olean-12-ene (6) and 3alpha,21beta-dihydroxy-11alpha-methoxy-urs-12-ene, isolated as its diacetate derivative (7), as well as 3alpha,21beta-dihydroxy-olean-12-ene (1) previously isolated from the root bark. The known alpha- and beta-amyrin, oleanoic and ursolic acids, trans-polyisoprene, and the ubiquitous beta-sitosterol were also isolated. Structures were elucidated on the basis of spectroscopic analyses, including homo- and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC and HMBC) and comparison with literature data. The antigiardial activity of compounds 2-5 was not significant.     

Microbiological transformation of two labdane diterpenes, the main constituents of Madia species, by two fungi

Microbial transformation of 13R,14R,15-trihydroxylabd-7-ene (5) and 13R,14R,15-trihydroxylabd-8(17)-ene (6) by the fungus Debaryomyces hansenii gave 1 (13R,14R,15-trihydroxy-6-oxolabd-8-ene) and 3 (7alpha,13R,14R,15-tetrahydroxy-labd-8(17)-ene), respectively. While, microbial transformation of 5 by Aspergillus niger afforded 2 (3beta,13R,14R,15-tetrahydroxy-labd-7-ene), and 13R,14R,15-trihydroxylabd-8,17-ene (6) gave 3 and 4 (3R,14R,15-3-oxotetrahydroxy-labd-7-ene). The structures of the new compounds, 1 and 2, were assigned by 1D and 2D high-field NMR spectroscopic methods. Antimicrobial activity of these compounds were tested and their MIC were determined.     

Antifungal highly oxygenated guaianolides and other constituents from Ajania fruticulosa.

Three highly oxygenated guaianolides were isolated from the aerial parts of Ajania fruticulosa along with 17 known phytochemicals including a triterpene (alpha-amyrin), two plant sterols (beta-sitosterol, daucosterol), four flavonoids (axillarin, centaureidin, santin and 5,7,4'-trihydroxy-3,3'-dimethoxyflavone), and ten sesquiterpenes [1alpha-hydroperoxy-4beta,8alpha,10alpha,13-tetrahydroxyguaia-2-en-12,6alpha-olide, 1alpha-hydroperoxy-4alpha,10alpha-dihydroxyguaia-9alpha-angeloyloxyguaia-2,11(13)-dien-12,6alpha-olide, 3beta,4alpha-dihydroxyguaia-11(13),10(14)-dien-12,6alpha-olide, 1alpha,4alpha,10alpha-trihydroxy-9alpha-angeloyloxyguaia-2,11(13)-dien-12,6alpha-olide, 1beta,2beta-epoxy-3beta,4alpha,10alpha-trihydroxy-guaia-11(13)-en-12,6alpha-olide and 2-oxo-8alpha-hydroxyguaia-1(10),3,11(13)-trien-12,6alpha-olide, ketoplenolide B, alantolactone, 9beta-hydroxyeudesma-4,11(13)-dien-12-oic acid and 9beta-acetoxyeudesma-4,11(13)-dien-12-oic acid]. The structures of the three guaianolides were elucidated by a combination of spectroscopic methods (EIMS, HREIMS, COSY, HMQC, HMBC and NOESY) as 1beta,2beta-epoxy-3beta,4alpha,8beta,10alpha-tetrahydroxyguaia-11(13)-en-12,6alpha-olide (1), 1beta,2beta-epoxy-3beta,4alpha,9alpha,10alpha-tetrahydroxyguaia-11(13)-en-12,6alpha-olide (2) and 1beta,2beta-epoxy-10alpha-hydroperoxy-3beta,4alpha,8beta-trihydroxyguaia-11(13)-en-12,6alpha-olide (3), respectively. Antifungal bioassay of all isolates showed that guaianolides 1, 2, 3, and 1beta,2beta-epoxy-3beta,4alpha,10alpha-trihydroxyguaia-11(13)-en-12,6alpha-olide were inhibitory to the growth of Candida albicans with MICs being 20, 20, 20, and 40 microg/ml, respectively.     

Tetra- and hexahydro derivatives of aldosterone and 18-hydroxycorticosterone by chemical and microbial reductions

Preparative methods were developed for reduction with NaBH4 at 0 of 3 beta, 5 alpha- and 3 alpha, 5 beta-tetrahydroaldosterone (1) and (12) to their respective 20 alpha-ol derivatives 2a and 13a. Corroboration of structures was obtained by periodate oxidations to the lactols 3b and 14b and thence, by further oxidation, to the lactones 4 and 15 respectively; these lactones were also independently obtained from 1 and 12. Reduction with NaBH4 at 80 degrees C converted 1 and 12 into 18-hydroxy-3 beta, 5 alpha, 20- and 18-hydroxy-3 alpha, 5 beta, 20-hexahydrocorticosterone 6a and 17a respectively, which were mixtures of epimers at C-20. Compound 17a could also be prepared by reduction of the lactone 21 with sodium aluminum bis-(methoxyethoxy) hydride. Again, periodate oxidations of 6a and 17a gave the lactols 7b and 22b and thence, by Jones oxidation, the diketolactones 8 and 23, which were also prepared from 18-hydroxy-11-dehydrocorticosterone (10) and 18-hydroxycorticosterone (24) respectively. Improved conditions for reduction with Clostridium paraputrificum permitted convenient conversion of aldosterone (11), the corresponding 18 leads to 11 lactone 18a and 18-hydroxycorticosterone (24) into their 3 alpha, 5 beta-tetrahydro derivatives.     

Hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by rat prostate microsomes: effects of antibodies and chemical inhibitors of cytochrome P450 enzymes.

The purpose of the present study was to test the hypothesis that rat prostate microsomes contain a single cytochrome P450 enzyme responsible for the conversion of 5 alpha-androstane-3 beta,17 beta-diol to a series of trihydroxylated products. The three major metabolites formed by in vitro incubation of 5 alpha-[3H]androstane-3 beta,17 beta-diol with rat prostate microsomes were apparently 5 alpha-androstane-3 beta,6 alpha,17 beta-triol, 5 alpha-androstane-3 beta,7 alpha,17 beta-triol, and 5 alpha-androstane-3 beta,7 beta,17 beta-triol, which were resolved and quantified by reverse-phase HPLC with a flow through radioactivity detector. The ratio of the three metabolites remained constant as a function of incubation time, microsomal protein concentration, ionic strength, and substrate concentration. The ratio of the three metabolites was dependent on pH, apparently because the hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol shifted from the 6 alpha- to the 7 alpha-position with increasing pH (6.8-8.0). The V(max) values were 380, 160, and 60 pmol/mg microsomal protein/min for the rate of 6 alpha-, 7 alpha-, and 7 beta-hydroxylation, respectively. Similar Km values (0.5-0.7 microM) were measured for enzymatic formation of all three metabolites, which suggests that formation of all three metabolites was catalyzed by a single, high-affinity enzyme. Testosterone, 5 alpha-dihydrotestosterone, and 5 alpha-androstane-3 alpha,17 beta-diol did not appreciably inhibit the hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol, suggesting that this enzyme exhibits a high degree of substrate specificity. Formation of all three metabolites was inhibited by antibody against rat liver NADPH-cytochrome P450 reductase (85%) and by a 9:1 mixture of carbon monoxide and oxygen (60%). Several chemical inhibitors of cytochrome P450 enzymes, especially the antimycotic drug clotrimazole, also inhibited the formation of all three metabolites. Polyclonal antibodies that recognize liver cytochrome P450 1A, 2A, 2B, 2C, and 3A enzymes did not inhibit 5 alpha-androstane-3 beta,17 beta-diol hydroxylase activity. Overall, these results are consistent with the hypothesis that the 6 alpha-, 7 alpha-, and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by rat prostate microsomes is catalyzed by a single, high-affinity P450 enzyme. This cytochrome P450 enzyme appears to be structurally distinct from those in the 1A, 2A, 2B, 2C, and 3A gene families.     

Long-chain fatty acid esters of 5-androstene-3 beta, 17 beta-diol: composition and turnover in human mammary cancer cells in culture

Long-chain fatty acid esters of the adrenal-derived estrogen 5-androstene-3 beta, 17 beta-diol (ADIOL) were found to accumulate in four human mammary cancer cell lines (MCF-7, ZR-75-1, MDA-MB-231 and MDA-MB-330) when explosed to 10-30 nM ADIOL for variable time periods. At each time point examined, the monoester fraction, which represented the major component of the total lipoidal fraction, contained fatty acids linked to either the 3 beta- or 17 beta-positions. However, there was considerable variation in the ratio of 3 beta- to 17 beta-monoesters in the four cell lines. By means of reverse phase HPLC and referral to authentic synthesized compounds, each monoester fraction was found to contain a number of long-chain fatty acid components whose composition resembled that previously determined for the fatty acid esters formed from 17 beta-estradiol. A specific and measurable turnover of a subfraction of ADIOL-17 beta-monoesters composed of essential fatty acids (22:6, 20:4, 18:3) occurred in MCF-7 cells, and to a lesser extent in ZR-75-1 cells. No changes were observed with time in any of the components of the 3 beta- or 17 beta-monoester fractions in MDA-MB-231 and MDA-MB-330 cells. These results, coupled with other studies, now suggest that a very rapid turnover of some components of these lipoidal derivatives may be occurring. If so, it is possible that the system of acylation-deacylation may be involved in a transport mechanism for estrogens and perhaps other steroid hormones.     

Cytotoxic triterpenoid saponins from the fruits of Aesculus pavia L

Continued chemical investigation on the fruits of North American Aesculus pavia L. resulted in the isolation and identification of 13 polyhydroxyoleanene pentacyclic triterpenoid saponins, named aesculiosides IIe-IIk (1-7), and IIIa-IIIf (8-13), together with 18 known compounds: aesculiosides Ia-Ie (14-18), IIa-IId (19-22), IVa-IVc (23-25), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,15 alpha,16 alpha,21 beta,22 alpha,28-hexahydroxyolean-12-ene (26), 3-O-[beta-D-glucopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,24 beta,28-hexahydroxyolean-12-ene (27), 3-O-[beta-D-galactopyranosyl(1-->2)]-alpha-L-arabinofuranosyl(1-->3)-beta-D-glucuronopyranosyl-21,22-O-diangeloyl-3beta,16 alpha,21 beta,22 alpha,28-pentahydroxyolean-12-ene (28), R(1)-barrigenol (29), scopolin (30), and 5-methoxyscopolin (31). The structures of these compounds were elucidated by spectroscopic and chemical analyses. Compounds 14-22 and 26-28 were tested in vitro for their activity against 59 cell lines from nine different human cancers including leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast. It was found that compounds with two-acyl groups at C-21 and C-22 had cytotoxic activity for all cell lines tested with GI(50) 0.175-8.71 microM, while compounds without acyl groups at C-21 and C-22 had weak or no cytotoxic activity. These results suggest that the acyl groups at C-21 and C-22 are essential for their activity.     

Taxanes with C-5-amino-side chains from the needles of Taxus canadensis

Five taxanes with an amino-side chain on C-5 were identified for the first time in the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 2alpha,7beta,9alpha,10beta,13-pentaacetoxy-11beta-hydroxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),12-diene (1), 2alpha,9alpha-dihydroxy-10beta,13alpha-diacetoxy-5alpha-(3'-methylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (2), 2alpha17-dihydroxy-9alpha,10beta,13alpha-triacetoxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (3), 2alpha-hydroxy-7beta,9alpha,10beta,13alpha-tetraacetoxy-5alpha-(2'-hydroxy-3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (4), and 9alpha-hydroxy-2alpha,10beta,13alpha-triacetoxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (5) on the basis of 1D-, 2D-NMR spectroscopic data and high-resolution fast atom bombardment MS analyses. Metabolite (1) was isolated from the needles of the Canadian yew for the first time but had previously been detected in the stems of the Japanese yew, whereas taxanes (2-5) are only now reported. Metabolite (3) is the first reported nitrogen-containing taxane with a 17-hydroxyl substitution.     

Etoposide: a new approach to the synthesis of 4-O-(2-amino-2-deoxy-4,6-O-ethylidene-beta-D-glucopyranosyl)-4'-O- demethyl-4-epipodophyllotoxin

Synthesis of 3-O-acetyl-2-benzyloxycarbonylamino-2-deoxy-4,6-O-ethylidene- alpha-(7 alpha) and-beta-D-glucopyranose (7 beta) and their 3-O-chloroacetyl analogues (11 alpha and 11 beta) are described. Condensation (BF3-etherate, ethyl acetate, -20 degrees) of 7 alpha with 4'-O-benzyloxycarbonyl-4'-O-demethyl-4-epipodophyllotoxin (8) afforded mainly the beta-glycoside 9 beta (alpha, beta-ratio 1:9). Condensation of 11 alpha beta with 8 or the 4'-O-chloroacetyl analogue 13 gave mainly the 4-O-(2-benzyloxycarbonylamino-3-O-chloroacetyl-2-deoxy-4,6-O-ethyl idene-beta-D- glucopyranosyl)-epipodophyllotoxin 12 beta or 15 beta. Glycosidation of podophyllotoxin (14) with 11 alpha beta (during which the aglycon epimerized at C-4 under the action of BF3-etherate) afforded alpha- (16 alpha) and beta-glycoside (16 beta) in the ratio 1:5. Removal of the chloroacetyl groups from 12 beta, its alpha analogue 12 alpha, and 15 beta gave the 4-O-(2-benzyloxycarbonylamino-2-deoxy-4,6-O-ethylidene-alpha-(17 alpha) and -beta-D-glucopyranosyl)-4'-O-demethyl-epipodophyllotoxins (17 beta and 20 beta), respectively. Hydrogenolysis of the benzyloxycarbonyl groups then gave 4-O-(2-amino-2-deoxy-4,6-O-ethylidene-alpha- (18 alpha) and -beta-D-glucopyranosyl)-4'-O-demethyl-4-epipodophyllotoxin (18 beta). Reductive alkylation of 18 beta and 18 alpha afforded the 2"-deoxy-2"-dimethylamino-etoposide 3 and its alpha analogue 19 alpha.     

Alternate hydroxylating activities in newborn rat adrenal cells in primary culture

During the course of a study to produce reference compounds, the metabolism of tetrahydrogenated derivatives (ring A reduced) of progesterone, 6 alpha-hydroxyprogesterone, 11-deoxycorticosterone and corticosterone in newborn rat adrenal cells in primary culture was studied. Analysis of the metabolites was made by gas chromatography-mass spectrometry. Most products resulted from the enzymatic reactions of 11 beta-, 18- and 21-hydroxylation, reduction of the 20-oxo group and oxidoreduction of the 3-hydroxyl group. However, unexpected metabolites were produced from the incubation of 3 beta, 5 alpha-tetrahydroprogesterone and 6 alpha-hydroxy-3 alpha, 5 beta-tetrahydroprogesterone. They resulted from the 16 alpha-hydroxylation of the precursors and probably from the 15 alpha-, 16 beta- and 17 alpha-hydroxylation of 6 alpha-hydroxy-3 alpha, 5 beta-tetrahydroprogesterone. These hydroxylating activities are weak and were not detected from the endogenous steroidogenesis. They were not detected either from the incubation of exogenous steroids with a 3-oxo-4-ene structure or from steroids with a 21-hydroxyl substituent. They result only from substrates showing diminished or no affinity towards the 11 beta/18- and 21-steroid hydroxylase systems. These unusual hydroxylations could be catalyzed by monooxygenase systems in the endoplasmic reticulum similar to those present in the liver or by the monooxygenase systems specific to steroidogenesis. In particular, the reaction specificity of cytochrome P-450(11) beta could be altered by the presence of a 6 alpha-hydroxyl group in a tetrahydrogenated steroid.     

Synthesis and biological evaluation of some 17-picolyl and 17-picolinylidene androst-5-ene derivatives

Starting from dehydroepiandrosterone (1) 17-picolyl (2), 17-picolinylidene (7), 17-picolinylidene-16-one (10 and 11), and 17-picolyl-16-one (15) derivatives of androst-5-ene were synthesized in one, two, four and five steps respectively. By the Oppenauer oxidation or dehydration of 2, 7, 10, and 11 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), the corresponding A and B ring modified derivatives 3, 5, 6, 8, 9, and 12-14 were obtained. The structure of 2 was unambiguously proved by the appropriate X-ray structural analysis. Compounds 3, 5, 9, 12-14 showed inhibitory activity against the enzyme aromatase. Antibacterial activity, toxicity to brine shrimp Artemia salina, antitumor activity against three tumor cell lines (human cervix carcinoma HeLa cells, human melanoma FemX cells, and human myelogenous leukemia K562 cells) and toxicity against peripheral blood mononuclear cells were evaluated. Three tested compounds, namely 11, 13, and 15, showed strong activity against all three cell lines, the IC(50) values being in the range of 4-10 microM.     

Synthesis of unique 17beta-estradiol homo-dimers, estrogen receptors binding affinity evaluation and cytocidal activity on breast, intestinal and skin cancer cell lines

A rapid and efficient synthesis of a series of C2-symmetric 17beta-estradiol homo-dimers is described. The new molecules are linked at position 17alpha of the steroid nucleus with either an alkyl chain or a polyethylene glycol chain. They are made from estrone in only five chemical steps with an overall yield exceeding 30%. The biological activity of these compounds was evaluated in vitro on estrogen dependent and independent (ER+ and ER-) human breast tumor cell lines: MCF-7 and MDA-MB-231. Some of the dimers present selective cytotoxic activity against the ER+ cell line. However, they are not very cytotoxic when compared to the antiestrogen tamoxifen. Unfortunately, they show only weak affinity for the estrogen receptor alpha (ERalpha) and no affinity for the estrogen receptor beta (ERbeta). The new compounds were also tested on human intestinal (HT-29) cancer and on murine skin cancer (B16-F10) cell lines for further biological assessment. Interestingly, the dimers were found to be cytotoxic to the murine skin cancer cell line but were inactive towards the intestinal cancer cell line.     

Pituitary metabolism of 5alpha-androstane-3beta-17beta-diol: intense and rapid conversion into 5alpha-androstane-3beta,6alpha,17beta-triol and 5alpha-androstane-3beta,7alpha, 17beta-triol.

In the male rat pituitary, 5alpha-androstane-3beta, 17beta-diol (3beta-diol) is extensively metabolized into polar steroids. They were identified as 5alpha-androstane-3beta, 6alpha-17beta-triol (6alpha-triol) and 5alpha-androstane-3beta, 7alpha, 17beta-triol (7alpha-triol). 6-alpha-Triol represents 53% and 7alpha-Triol 28% of the total 3beta-diol metabolites. The remaining percentage is related to 6beta and 7beta isomers. The biological role of triols is still unknown.