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.     

Epoxidation and reduction of cholesterol, 1,4,6-cholestatrien-3-one and 4,6-cholestadien-3beta-ol

Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. This paper describes reagent and position selectivity of epoxidation and reduction of cholesterol derivatives. Cholesterol was reacted with m-chloroperoxybenzoic acid (m-CPBA) to form 5alpha,6alpha-epoxycholestan-3beta-ol, but in reaction with 30% H(2)O(2), it did not reacted. 1,4,6-cholestatrien-3-one was obtained from cholesterol and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. 1,4,6-cholestatrien-3-one was reacted with 30% H(2)O(2) and 5% NaOH in methanol to give 1alpha,2alpha-epoxy-4,6-cholestadien-3-one, which was stereoselectively reduced with NaBH(4) to form 1alpha,2alpha-epoxy-4,6-cholestadien-3beta-ol and reduced with Li metal in absolute ethanol to give 2-ethoxy-1,4,6-cholestatrien-3-one. And 1,4,6-cholestatrien-3-one was epoxidized with m-CPBA in dichloromethane to afford 6alpha,7alpha-epoxy-1,4-cholestadien-3-one, which was reacted with NaBH(4) to synthesize 6alpha-hydroxy-4-cholesten-3-one and reduced Li metal in absolute ethanol to form 2-ethoxy-1,4,6-cholestatrien-3-one, respectively. 1,4,6-cholestatrien-3-one was reduced with NaBH(4) in absolute ethanol to form 4,6-cholestadien-3beta-ol, which was reacted with 30% H(2)O(2) to leave original compound, but was reacted with m-CPBA to give 4beta,5beta-epoxy-6-cholesten-3beta-ol as the major product and 4beta,5beta-epoxy-6alpha,7alpha-epoxycholestan-3beta-ol as the minor product.     

Stereospecific 1,4-addition to an alpha,beta-unsaturated steroidal epoxide: syntheses of new 15-oxygenated sterols

3 beta-Benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene (1) is a key intermediate in the synthesis of C-7 and C-15 oxygenated sterols. Treatment of 1 with benzoyl chloride resulted in the formation of 3 beta,15 alpha-bis-benzoyloxy-7 alpha-chloro-5 alpha-cholest-8(14)-ene (2). Reaction of 2 with LiAlH4 or LiAlD4 resulted in the formation of 5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3a) or [14 alpha-2H]5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3b). Diol 3b was selectively oxidized by Ag2CO3/celite to [14 alpha-2H]5 alpha-cholest-7-en-15 alpha-ol-3-one (4). Treatment of 1 with MeMgI/CuI gave 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 alpha-diol (5). Selective oxidation of 5 with pyridinium chlorochromate (PCC)/pyridine or oxidation with PCC resulted in the formation of 7 alpha-methyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one (6) and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3,15-dione, respectively. Reduction of 6 with LiAlH4 yielded 5 and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 beta-diol (6). Reaction of 1 with benzoic acid/pyridine gave 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-en-15 alpha-ol (9). Treatment of 9 with LiAlH4 or ethanolic KOH resulted in the formation of 5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol (10). Dibenzoate 9, upon brief treatment with mineral acid, gave 3 beta-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (11). Oxidation of 9 with PCC yielded 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (12). Ketone 12 was also prepared by the selective hydride reduction of 5 alpha-cholest-8(14)-en-7 alpha-ol-3,15-dione (13) to give 5 alpha-cholest-8(14)-ene-3 beta,7 alpha-diol-15-one (14), which was then treated with benzoyl chloride to produce 12.     

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.     

X-ray and deuterium labeling studies on the abnormal ring cleavages of a 5 beta-epoxide precursor of formestane

A new convergent synthesis of the antitumor steroid formestane (4-OHA) 5 has been performed from the easily available epimeric mixture of 5 alpha- and 5 beta-androst-3-en-17-one 1a and 1b in order to attempt a yield improvement. A two-step oxidative route followed by base-catalyzed isomerization was applied to the 5 alpha- and 5 beta-epimers 1a and 1b, either as a mixture or separately, leading to the title compound 5. From epimer 1a an efficient process was attained to prepare the desired aromatase inhibitor formestane. Epimer 1b led to the formation of the same compound 5. Additionally, 1b have also been converted in 5 beta-hydroxyandrostane-3,17-dione 12 and androst-4-ene-3,17-dione 13, revealing an unexpected reactivity of the 3 beta,4 beta-epoxy-5 beta-androstan-17-one intermediate 6 formed from 1b during the first oxidative step with performic acid. Cleavage of the epoxide 6 led to the trans-diaxial and the trans-diequatorial vic-diols 7 and 8 and to the 1,3-diol 9. The formation of the abnormal products 8 and 9 were investigated through X-ray and deuterium labeling studies. Diol 8 was formed through a trans-diequatorial epoxide ring opening and the 1,3-diol 9 was formed through an intramolecular rearrangement involving a 1,2-hydride shift. All the vic-diols 3, 7 and 8 formed, proved to be good precursors for the synthesis of the target compound 5.     

Studies of the oxysterol inhibition of tumor cell growth

The oxysterols 3 beta-hydroxy-5 alpha-cholest-8-en-11-one, 3 beta-hydroxy-5 alpha-cholest-8-en-7-one, 3 beta-hydroxy-5 alpha-cholest-8(14)-en-7-one, 3 beta-hydroxy-4,4'-dimethylcholest-5-ene-7 one, 4,4'-dimethylcholest-5-ene-3 beta, 7 alpha-diol, 4,4'-dimethylcholest-5-ene-3 beta, 7 beta-diol, lanost-8-ene-3 beta, 25-diol, 25-hydroxylanost-8-en-3-one, 9 alpha, 11 alpha-epoxy-5 alpha-cholest-7-en-3 beta-ol, 3 beta-hydroxycholest-5 alpha-en-22-one, and 3 beta-hydroxycholest-5-en-22-one oxime were evaluated with respect to their ability to inhibit cell growth. All of the sterols were found to possess cytotoxicity when incubated with hepatoma (HTC) and lymphoma (RDM-4) cells in culture at 10-30 microM concentrations.     

The reactions of palladium(II), thallium(III) and lead(IV) trifluoroacetates with 3beta-acetoxyandrost-5-en-17-one: crystal structure of the first trifluoroacetate bridged 5,6,7-pi-allyl steroid palladium dimer

A number of metal trifluoroacetates were reacted with the olefin 3beta-acetoxyandrost-5-en-17-one (6). Palladium(II) trifluoroacetate afforded bis[micro-trifluoroacetato(alpha-5,7-eta-3beta-acetoxyandrostenyl-17-one)palladium(II)] (20), a new ring B pi-allyl steroid-palladium complex, in quantitative yield. Thallium(III) trifluoroacetate gave 3beta-acetoxy-5alpha-hydroxy-6beta-trifluoroacetoxyandrostan-17-one (16), 3beta-acetoxy-6beta-trifluoroacetoxyandrost-4-en-17-one (9), 3beta-acetoxy-4beta-trifluoroacetoxyandrost-5-en-17-one (10), and 3beta-acetoxy-5alpha,6beta-dihydroxyandrostan-17-one (17). Lead(IV) trifluoroacetate yielded 9, 10 and 16. 3beta-Acetoxy-5alpha,6beta-bis(trifluoroacetoxy)androstan-17-one (15), a new compound, was also formed in this reaction. During the course of the lead(IV) studies the dichlorosteroid 21 and the rearranged allylic oxidation product 24 were formed. Their formation was attributed to the generation of lead(IV) chloride in the reaction. Silver(I) and copper(II) trifluoroacetates proved to be unreactive towards 6.     

A new chemical synthesis of 5alpha-cholest-8(14)-en-3beta,5alpha-diol

Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with lithium in ethylenediamine gave 5alpha-cholest-8(14)-en-3beta, 5alpha-diol in high yield. This procedure offers an alternate synthesis through the reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide.     

Steroid hydroxylation by Whetzelinia sclerotiorum, Phanerochaete chrysosporium and Mucor plumbeus

The fungi Whetzelinia sclerotiorum ATCC 18687, Phanerochaete chrysosporium ATCC 24725 and Mucor plumbeus ATCC 4740 were examined for their ability to perform steroid biotransformations under single phase, pulse feed conditions. The steroids 3beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone) (1), 17beta-hydroxyandrost-4-en-3-one (testosterone) (5), 3beta-hydroxypregn-5-en-20-one (pregnenolone) (3), pregn-4-ene-3,20-dione (progesterone) (9), 17alpha,21-dihydroxypregn-4-ene-3,11,20-trione (cortisone) (11), 17alpha,21-dihydroxypregna-1,4-diene-3,11,20-trione (prednisone) (14), and 3-hydroxyestra-1,3,5(10)-trien-17-one (estrone) (15) were fed to each fungus. The production of a number of novel metabolites is reported. Of the fungi investigated W. sclerotiorum performed the most interesting biotransformations and had a clear propensity for 2beta, 6beta/7beta and 15beta/16beta hydroxylations. P. chrysosporium was more prone functionalize steroids in the allylic position. Oxygen insertion at C-14 by M. plumbeus is reported for the first time. All three micro-organisms exhibited redox activity.     

One-pot synthesis of new A-ring fused steroidal pyridines

The preparation of pyridine rings fused to the 3,4-positions of the steroid nucleus is herein described. These new pyridine derivatives were prepared in good yields by the reaction of propargylamine with 17beta-hydroxyandrost-4-en-3-one, 17alpha-methyl-17beta-hydroxyandrost-4-en-3-one, 17beta-hydroxyestr-4-en-3-one catalyzed by Cu(II). The structure of 17beta-hydroxy-5-ene-androst-3-eno[3,4-b]pyridine was determined by X-ray analysis.     

The in vitro and in vivo reaction at the N7-position of guanine of the ultimate carcinogen derived from benzolalpyrene.

The previously reported reaction at N2- and N7- of guanine following addition of 7 alpha,8 beta-dihydroxy-9 beta, 10 beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE) to an aqueous solution of DNA has been studied in more detail. The extent of reaction and the relative yields of N2- and N7-products was measured over the range of pH 4--7. The depurination following reaction at the N7-position of guanine was found to have a half-life of 3 h. Reaction of the isomeric 7 alpha,8 beta-dihydroxy-9 alpha, 10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]-pyrene (syn-BPDE) with DNA gave the expected N2- and no N7-guanine product. When either benzo[a]pyrene or anti-BPDE was added to mouse embryo or Chinese hamster V79 cells respectively, a major N2-guanine product and a very minor adenine product were isolated from the DNA, but no N7-guanine product was detected.     

CH(3)ReO(3)-catalyzed oxidation of cholesta-5,7-dien-3beta-yl acetate with the urea-hydrogen peroxide adduct under various conditions. Synthesis of the natural epoxy sterol 9alpha,11alpha-epoxy-5alpha-cholest-7-en-3beta,5,6beta-triol

This article describes the oxidation of cholesta-5,7-dien-3beta-yl acetate (4) with the urea-hydrogen peroxide adduct (UHP) using methyltrioxorhenium (MTO) as catalyst, under various conditions. Specifically, the effects of using different solvents (CHCl(3) and ethers) and additives (EtOH and pyridine) on the course of the MTO-catalyzed oxidation of 4 were investigated. Some new steroids (6, 9, 10 and 11), obtained from this oxidation, were isolated and characterized on the basis of chemical evidence and interpretation of spectroscopic data including H-H COSY and HMBC experiments. The optimal solvent for the oxidation of 4 with MTO/UHP oxidizing system was diethyl ether. In this solvent the reaction is clean and gave as the main product 5,6beta-dihydroxy-5alpha-cholest-7-en-3beta-yl acetate (8, 65% yield), obtained with a more simple procedure and with a higher yield than that reported in literature. Sterol 8 is a key intermediate compound in the synthesis of many steroids of marine origin, biologically active, oxygenated at the B/C rings. In fact, starting from diol 8, we performed the synthesis of the natural cytotoxic epoxy sterol 9alpha,11alpha-epoxy-5alpha-cholest-7-en-3beta,5,6beta-triol (15, 21% yield) with an improvement in yield and number of steps over a synthesis of the same natural product previously reported. When the oxidation of 4 with the MTO/UHP system in diethyl ether was performed in the presence of pyridine as ligand, the unsaturated epoxide 5,6alpha-epoxy-5alpha-cholest-7-en-3beta-yl acetate (10, 90% yield) was obtained after only 5 min in good yield. In fact, pyridine, besides having beneficial effect on the reaction rate, shuts down the ring opening reactions, as reported in literature.     

Synthesis of the marine epoxy sterol 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol

The synthesis of 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol (1), a highly oxygenated marine sterol containing a 9,11-epoxide moiety in the nucleus, is described. Epoxy sterol 1 was synthesized from cholesta-5,7-dien-3 beta-ol. Oxidation of this sterol with m-chloroperbenzoic acid followed by hydrolysis and acetylation furnished 5 alpha-cholest-7-ene-3 beta,5,6 alpha-triol 3,6-diacetate (2). Mercuric acetate dehydrogenation of diacetate 2, followed by oxidation with manganese dioxide and epoxidation with m-chloroper-benzoic acid, afforded 9 alpha,11 alpha-epoxy-3 beta,5-dihydroxy-5 alpha-cholest-7-en-6-one (5). Reduction of 5 with lithium aluminum hydride gave the desired compound 1. The structures of all synthetic intermediates were confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. A reassignment of resonances for carbons 1, 8, and 15 in the 13C NMR spectrum of 1, based on 2D-NMR correlation spectroscopy, has been accomplished.     

The altered specificity of cortisone reductase with certain retroandrostan-3-one substrates.

The retro steroids 17beta-hydroxy-5beta,9beta,10alpha-androstan-3-one and 5beta,9beta,10alpha-androstane-3,17-dione were good substrates for cortisone reductase in the presence of NADH, and the products corresponded to the respective 3beta-hydroxy compounds, in which the 3beta-hydroxyl group is axial and the absolute configuration is 3S. The analogous natural steroids 17beta-hydroxy-5beta,9alpha,10beta-androstan-3-one and 5beta,9alpha,10beta-androstane-3,17-dione were very poor substrates, and gave the corresponding 3alpha(equatorial,3R)-hydroxy compounds, and, in the latter case, also an appreciable amount of 3beta(axial, 3S)-hydroxy-5beta,9alpha,10beta-androstan-17-one. The natural steroids 17beta-hydroxy-5alpha,9alpha,10beta-androstan-3-one and 5alpha,9alpha,10beta-androstane-3,17-dione were better substrates than the retro steroid 17beta-hydroxy-5alpha,9beta,10alpha-androstan-3-one, but were not such good substrates as the retro steroids 17beta-hydroxy-5beta,9beta,10alpha-androstan-3-one and 5beta,9beta,10alpha-androstane-3,17-dione. Unlike these retro steroid 5beta,9beta,10alpha-androstan-3-ones, the natural steroids 17beta-hydroxy-5alpha,9alpha,10beta-androstan-3-one and 5alpha,9alpha,10beta-androstane-3,17-dione gave the corresponding 3alpha(axial,3R)-hydroxy compounds. The retro steroid 17beta-hydroxy-5alpha,9beta,10alpha-androstan-3-one was not a good substrate, and the product of reaction corresponded to the 3alpha(axial,3R)-hydroxy compound. The nature of substrate recognition by this enzyme is discussed in the light of these structure-activity relationships.     

Synthesis of (25R)-26-hydroxy-15-ketosterols

(25R)-3beta,26-Dihydroxy-5alpha-cholest-8(14)-en-15-one (1) and (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2) were synthesized from (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-ene (4). Oxidation of 4 with CrO3-3,5-dimethylpyrazole at -20 degrees C gave (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-en-15-one (5) along with (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-16alpha+ ++,17alpha-epoxide (6). Oxidation of 5 with selenium dioxide afforded (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-8(14),16-++ +dien-15-one (7) and (25R)-3beta,26-dibenzoyloxy-5alpha,14beta-choles t-16-en-15-one (8). Selective hydrogenation of 7 followed by hydrolysis in alcoholic potassium hydroxide yielded (25R)-3beta,26-dihydroxy-5alpha-cholest-8(14)-en-15-one (1). Hydrolysis of 5 and 8 in alcoholic potassium hydroxide provided (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2).     

Microbial transformation of 17alpha-ethynyl- and 17alpha-ethylsteroids, and tyrosinase inhibitory activity of transformed products

The microbial transformation of the 17alpha-ethynyl-17beta-hydroxyandrost-4-en-3-one (1) (ethisterone) and 17alpha-ethyl-17beta-hydroxyandrost-4-en-3-one (2) by the fungi Cephalosporium aphidicola and Cunninghamella elegans were investigated. Incubation of compound 1 with C. aphidicola afforded oxidized derivative, 17alpha-ethynyl-17beta-hydroxyandrosta-1,4-dien-3-one (3), while with C. elegans afforded a new hydroxy derivative, 17alpha-ethynyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (4). On the other hand, the incubation of compound 2 with the fungus C. aphidicola afforded 17alpha-ethyl-17beta-hydroxyandrosta-1,4-dien-3-one (5). Two new hydroxylated derivatives, 17alpha-ethyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (6) and 17alpha-ethyl-6alpha,17beta-dihydroxy-5alpha-androstan-3-one (7) were obtained from the incubation of compound 2 with C. elegans. Compounds 1-6 exhibited tyrosinase inhibitory activity, with compound 6 being the most potent member (IC(50)=1.72 microM).     

Synthesis of 3 beta,16 beta,19-trihydroxyandrost-5-en-17-one and 16 beta,19-dihydroxyandrost-4-ene-3,17-dione and their 19-oxo derivatives

3 beta,16 beta,19-Trihydroxyandrost-5-en-17-one (12) was synthesized from 5 alpha-bromo-3 beta-acetoxy-6 beta,19-epoxyandrostan-17-one (2) through acetoxylation at C-16 beta of the enol acetate 4 with lead tetraacetate and reductive cleavage of the epoxide ring with zinc dust yielding the 3 beta,16 beta-diacetoxy-19-hydroxy steroid 11, followed by hydrolysis of the acetoxy groups with sulfuric acid. Jones oxidation of compound 11 followed by the acid hydrolysis gave the 19-oxo steroid 15. 5 alpha-Bromo-3 beta-hydroxy-16 beta-acetoxy-6 beta,19-epoxyandrostan-17-one (8), obtained by selective hydrolysis of the 3-formate 5 with ammonium hydroxide, was oxidized with Jones reagent to afford the 3-oxo steroid 16, which was converted into the 19-hydroxy derivative 17 by treatment with zinc dust. 16 beta,19-Dihydroxyandrost-4-ene-3,17-dione (18) and its 19-oxo derivative 21 were obtained from compound 17 through a similar reaction sequence.     

Convenient synthesis of 18-hydroxylated cortisol and prednisolone.

18,20-Epoxy-11 beta,17 alpha,20 beta,21-tetrahydroxypregn-4-en-3-one was synthesized by the application of hypoiodite reaction to the cortisol acetonide. The intermediary 18-iodo derivative was converted to the 11-oxo steroid by chromic acid prior to silver ion-assisted solvolysis. Removal of the protective group with hydrochloric acid was finally carried out to give the desired 11 beta,17 alpha,18,21-tetrahydroxypregn-4-ene-3,20-dione as the hemiacetal form. 18,20-Epoxy-11 beta-17 alpha,20 beta,21- tetrahydroxypregna-1,4-dien-3-one was also prepared from prednisolone through a similar reaction sequence.     

Microbial transformation of mesterolone

The microbial transformation of mesterolone (= (1alpha,5alpha,17beta)-17-hydroxy-1-methylandrostan-3-one; 1), by a number of fungi yielded (1alpha,5alpha)-1-methylandrostane-3,17-dione (2), (1alpha,3beta,5alpha,17beta)-1-methylandrostane-3,17-diol (3), (5alpha)-1-methylandrost-1-ene-3,17-dione (4), (1alpha,5alpha,15alpha)-15-hydroxy-1-methylandrostane-3,17-dione (5), (1alpha,5alpha,6alpha,17beta)-6,17-dihydroxy-1-methylandrostan-3-one (6), (1alpha,5alpha,7alpha,17beta)-7,17-dihydroxy-1-methylandrostan-3-one (7), (1alpha,5alpha,11alpha,17beta)-11,17-dihydroxy-1-methylandrostan-3-one (8), (1alpha,5alpha,15alpha, 17beta)15,17-dihydroxy-1-methylandrostan-3-one (9), and (5alpha,15alpha,17beta)-15,17-dihydroxy-1-methylandrost-1-en-3-one (10). Metabolites 5-10 were found to be new compounds. All metabolites, except 2, 3, 6, and 7, exhibited potent anti-inflammatory activity. The structures of these metabolites were characterized on the basis of spectroscopic studies, and the structure of 5 was also determined by single-crystal X-ray-diffraction analysis.     

Differential inhibition of androst-4-en-3,17-dione aromatization by carbon monoxide in the presence of estr-4-en-3,17-dione.

The aromatization of androst-4-en-3,17-dione or 17beta hydroxyandrost-4-en-3-one (testosterone) is not inhibited by carbon monoxide under normal incubation conditions, whereas the aromatization of corresponding 19-nor steroids (estr-4-en-3,17-dione and 17beta-hydroxyestr-4-en-3-one) is readily inhibited under the same conditions. A possible explanation was found when it was shown that androst-4-en-3,17-dione and testosterone could displace bound carbon monoxide from human placental microsomal cytochrome P-450. The 19-nor steroids did not displace carbon monoxide, even at very high concentrations. These C-18 compounds appeared to facilitate complex formation and reversed the effects of the C-19 steroids. A mutual antagonism was observed with regard to effects on the formation of the ce titrated. These observations suggested that the aromatization of androst-4-en-3,17-dione should be inhibited by carbon monoxide if sufficient concentrations of the 19-nor steroids were present in reaction flasks. This hypotheses was tested and positive results were obtained, providing strong evidence for the involvement of cytochrome P-450 in normal estrogen biosynthesis.