Conversion of 20alpha-hydroxy-4-pregnen-3-one to 20alpha-hydroxy-5alpha-pregnan-3-one and 5alpha-pregnane-3alpha, 20alpha-diol by rat anterior pituitary

³H-20α-hydroxy-4-pregnen-3-one was incubated with anterior pituitaries from proestrous rats. The $\text{in vitro}$ metabolic products, identified by reverse isotopic dilution and purification to constant specific activity, were 20α-hydroxy-5α-pregnan-3-one (23.0%) and 5α-pregnane-3α,20α-diol (11.4%). These are qualitatively the same metabolites which result from $\text{in vitro}$ incubation of 20α-hydroxy-4-pregnen-3-one with medial basal hypothalamus. 68.8% of the recovered radioactivity remained as 20α-hydroxy-4-pregnen-3-one. These three compounds accounted for all of the recovered radioactivity.     

Microbial transformation of 5alpha,6alpha-epoxy-3beta-hydroxy-16-pregnen-20-one by Trichoderma viride

Fermentation of 5alpha,6alpha-epoxy-3beta-hydroxy-16-pregnen-20-one (4) with Trichoderma viride under aerobic condition yielded 3beta,5alpha,6beta-trihydroxy-16-pregnen-20-one (5) and 3beta,5alpha,6beta,15beta-tetrahydroxy-16-pregnen-20-one (6). Each microbial metabolite was characterized by spectroscopic methods. Compounds 6 and 3beta,5alpha,15beta-trihydroxy-16-pregnen-6,20-dione (7) are reported for the first time.     

Synthesis of the allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one and 3 alpha-hydroxy-4-androsten-17-one, and of 3 alpha-hydroxy-5 alpha-pregnan-20-one

A method for the convenient synthesis of the recently isolated allylic gonadal steroids, 3 alpha-hydroxy-4-pregnen-20-one (3 alpha-dihydroprogesterone; 3 alpha-DHP) and 3 alpha-hydroxy-4-androsten-17-one (3 alpha-HA), was developed using 4-pregnene-3,20-dione (progesterone) and 4-androstene-3,17-dione as substrates and potassium trisiamylborohydride (KS-Selectride) as reducing agent. Similar reactions were also used for the reduction of 5 alpha-pregnane-3,20-dione to 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-HP). The yields were about 15%, 50%, and greater than 90% for 3 alpha-DHP, 3 alpha-HA and 3 alpha-HP, respectively. Structures of the products, including the 3 beta-isomers and the 17 alpha-epimer, formed in these reactions were determined by NMR and mass spectroscopic methods.     

Synthesis of (5alpha)-17-azaandrostan-3-ols and (5alpha)-17-aza-D-homoandrostan-3-ols and their N-acylated derivatives.

Two groups of N-acylated D-azasteroids (4 and 5) were synthesized to explore structure-activity relationships for steroid modulation of GABA(A) receptor function. The target compounds were prepared conveniently from (5alpha)-3-hydroxyandrostan-17-ones (6 and 7) via the intermediate (5alpha)-17-aza-D-homoandrostan-3-ols (14 and 15) or (5alpha)-17-azaandrostan-3-ols (18 and 19) precursors in high overall yields. A Beckmann rearrangement and a Hofmann rearrangement were employed as two key steps in the synthetic sequences.     

Synthesis and antimicrobial evaluation of water-soluble, dendritic derivatives of epimeric 5alpha-cholestan-3-amines and 5alpha-cholestan-3-yl aminoethanoates

To examine the effect of negatively charged steroidal amphiphiles on antimicrobial activity, two pairs of epimeric, dendritic tricarboxylato amphiphiles--4-(2-carboxyethyl)-4-[3-(5alpha-cholestan-3-yl)ureido]heptanedioic acid (1) and 4-(2-carboxyethyl)-4-[3-(5alpha-cholestan-3-yloxycarbonylmethyl)ureido]heptanedioic acid (2)--were synthesized. A broad antimicrobial screen of 11 microbes revealed that these amphiphiles only showed good activity against a methicillin-resistant isolate of Staphylococcus aureus (MRSA) and modest activity against an unrelated strain of S. aureus. The best activity, a minimal inhibitory concentration (MIC) of 27 microM, was found for the 3beta epimer of 1 against MRSA.     

Acyl migration in the Reformatsky reaction of 21-acyloxy-5-pregnen-20-one derivatives with ethyl bromoacetate

Reformatsky reaction of 3β, 21-diacyloxy- and 3β-methoxy-21-acyloxy-5-pregnen-20-one with ethyl bromoacetate yields, through an intramolecular 1,2-acyl migration, 3β, 20ξ-diacyloxy- and 3β-methoxy-20ξ-acyloxy-14α-card-5-enolide respectively. The 20ξ-acyloxy-14α-card-5-enolides were converted into the respective 20ξ-hydroxy-14α-card-5-enolides and the 14α-carda-5,20(22)-dienolides. Experimental support to the proposed intramolecular 1,2-acyl migration is provided by the use of labelled compounds.     

A radioimmunoassay for the regulatory allylic steroid, 3 alpha-hydroxy-4-pregnen-20-one (3 alpha HP)

The allylic steroid, 3 alpha-hydroxy-4-pregnen-20-one (3 alpha HP), found in gonadal and brain tissues by radiotracer and chemical methods, had been shown to play a role in gametogenesis, gonadotropin secretion and brain excitability. Since no simple assay was available, a radioimmunoassay for 3 alpha HP was developed using [3H]3 alpha HP and an antiserum raised against 3 alpha HP-20-CMO conjugated to bovine serum albumin. The specificity of the assay for the 3 alpha allylic configuration of 3 alpha HP was confirmed by examining 32 other steroids; cross-reaction with steroids containing different configurations (including metabolites of 3 alpha HP such as progesterone) was less than 0.9%. A Scatchard plot indicated a Ka of 1.56 X 10(9) M-1. Inter- and intra-assay coefficients of variation were 13.1 and 4.5%, respectively. The sensitivity of the assay was 6 pg and the 50% intercept of the standard curve was approx. 123 pg. The measurement by RIA of 3 alpha HP from standard solutions and HPLC purified tissue extracts was confirmed qualitatively and quantitatively by GC/MS methods. The RIA method was employed to determine 3 alpha HP levels in cultured Sertoli cells and in serum of intact and ovariectomized adult rats. Although for most uses, chromatography would not be necessary, two possible methods are presented to enable the separation of 3 alpha HP from other interfering steroids prior to RIA.     

A simple synthesis of 3beta-acetoxy-20-oxomethylpregn-5-ene and 3beta-acetoxy-20-hydroxymethylpregn-5-ene

3beta-Acetoxy-20-oxomethylpregn-5-ene and 3beta-acetoxy-20-hydroxymethylpregn-5-ene were synthesized from (22R,23R)-sitost-5-ene-3beta,22,23-triol in 66% overall yields.     

Plasma membrane receptors for the cancer-regulating progesterone metabolites, 5alpha-pregnane-3,20-dione and 3alpha-hydroxy-4-pregnen-20-one in MCF-7 breast cancer cells

Recent observations indicate that the progesterone metabolite, 5alpha-pregnane-3,20-dione (5alphaP), which is produced at higher levels in tumorous breast tissue, promotes cell proliferation and detachment, whereas 3alpha-hydroxy-4-pregnen-20-one (3alphaHP), which is produced at higher levels in nontumorous breast tissue, suppresses proliferation and detachment of MCF-7 breast cancer cells. The objective of the current study was to determine the presence and characteristics of binding sites for these endogenous putative cancer-regulating steroid hormones. Radiolabeled 5alphaP and 3alphaHP were used in radioligand binding assays on MCF-7 cell (membrane, cytosolic, and nuclear) fractions. Binding of [(3)H]5alphaP and [(3)H]3alphaHP was observed only in the plasma membrane fraction, whereas estradiol binding sites were confirmed in the cytosolic and nuclear fractions. The respective membrane binding sites exhibited specificity for the 5alphaP and 3alphaHP ligands with no appreciable displacement at 200- to 500-fold excess by other steroids. The association rate constants were calculated as 0. 107/min and 0.0089/min and the dissociation rate constants were 0. 049 9 and 0.011 for 5alphaP and 3alphaHP, respectively. Saturation analyses indicated single classes of molecules with dissociation constants of 4.5 and 4.87 nM and receptor densities of 486 and 629 fmol/mg protein, respectively, for 5alphaP and 3alphaHP. Exposure of MCF-7 cells to estradiol for 1, 24, 48, and 72 h resulted in 2.3, 4. 2-, 2.99-, and 1.7-fold increases, respectively, in 5alphaP receptor density. 3alphaHP resulted in partial suppression of the estradiol-mediated increase in 5alphaP receptor density. This is the first report of receptors for the progesterone metabolites, 5alphaP and 3alphaHP, of their occurrence in breast cancer cell membranes, and of the induction of 5alphaP receptors by estradiol. The results provide further support for the potential importance of progesterone metabolites in breast cancer.     

Synthesis and antifungal activity of benzofuran-5-ols

Benzofuran-5-ol derivatives were synthesized and tested for in vitro antifungal activity against Candida, Aspergillus species, and Cryptococcus neoformans. Among them tested, many benzofuran-5-ols showed good antifungal activity. The results suggest that benzofuran-5-ols would be promising antifungal agents.