Pemmaraju N. Rao

Synthesis and antimitotic activity of novel 2-methoxyestradiol analogs.

The syntheses and antimitotic activity of several novel 2-methoxyestradiol analogs are described. Structural modifications investigated include introduction of additional unsaturation in rings B and D; inversion at C-13; and substitution at the C-2, C-15, C-16, and C-7 alpha positions. Of 15 analogs synthesized, 2 have demonstrated superior biological activities compared to 2-methoxyestradiol.

Enzyme immunosorbant assay of oestradiol in unextracted plasma using penicillinase as label

An enzyme-linked immunosorbant assay (ELISA) for measuring oestradiol directly in plasma without extraction utilizing antibodies raised against oestradiol-3-(O-carboxymethyl) ether-bovine serum albumin conjugate, and oestradiol-6-(O-carboxymethyl) oxime linked to penicillinase (EC 3.5.2.6) as a marker was developed. Polyvinyl 96-well microtitre plates were used for immobilization of anti-oestradiol IgG. Standards of oestradiol (92 to 9,190 pmol/l were prepared in oestradiol-free plasma and 8-anilino-1-naphthalene sulphonic acid (8-ANS, 5 mg/ml of 10 mmol/l PBS) was added to the microtitre plate wells to displace oestradiol from plasma binding proteins. The assay had a lower limit of detection of 92 pmol/l plasma and could be performed within 4 h. Comparison of oestradiol values of 51 plasma specimens obtained by ELISA with those of radioimmunoassay (RIA), in which oestradiol was extracted with diethyl ether, showed good correlation (y = 0.786x + 0.03; r = 0.900).

New 11β-aryl-substituted steroids exhibit both progestational and antiprogestational activity

The syntheses of three 11 beta-aryl-19-norpregna-4,9-dien-3-one derivatives with 17-spirolactone and 17 beta-hydroxy-17 alpha-cyanoethyl substitutions are described. The progesterone agonist/antagonist activities of the new compounds are investigated using a recently developed tissue culture system that relies on the progesterone agonist up-regulation of the prostate-specific antigen (PSA) gene in female breast tumor cell lines. Two of the newly synthesized compounds exhibit mixed agonistic/antagonistic progestational activity.

Enzyme immunoassay of cortisol in human plasma using penicillinase as label

An enzyme immunoassay for cortisol in human plasma using an antiserum raised against cortisol-3-O-carboxy-methyloxime bovine serum albumin and cortisol-21-hemisuccinate conjugated to penicillinase as tracer is described. Although employing immunoassay plates for separation of antigen-antibody complex from the free components was less time consuming, the slope and sensitivity of the standard curve were improved by the addition of goat anti-rabbit gamma globulin for precipitating the complex. There was good correlation between radioimmunoassay and enzyme immunoassay results obtained for cortisol levels present in normal human plasma.

Preparative chemical methods for aromatization of 19-nor-Δ4-3-oxosteroids ☆

Abstract Two preparative chemical methods for aromatization of 19-nor-Δ4-3-oxosteroids are described. The first method consist of an oxidative aromatization of 19-nor-Δ4-3-oxosteroids with iodine-ceric ammonium nitrate in methanol to give a mixture of 3-methoxy ring-A aromatized derivatives consisting of the desired product, the Δ9,11 derivative, the 6-oxo derivative as well as some ring-A iodinated material. Conversion of this material to a mixture of the 3-methoxy ring-A aromatized derivative and its 6-oxo derivative was achieved by catalytic hydrogenation. Finally, reduction of the 6-oxo function with triethylsilane in trifluoroactive acid gave the 3-methoxy-17-trifluoroacetate ring-A aromatized derivative as a single product. In the second method, reaction of 19-nor-Δ4-3-oxosteroids with copper (II) bromide in acetonitrile at room temperature resulted in aromatic steroids in a single in excellent yields. The second method was used in the first practical synthesis of a 6-dehydroestrogen from a 19-nor-Δ4,6-3-oxosteroid.

Influence of different combinations of antibodies and penicillinase-labeled testosterone derivatives on sensitivity and specificity of immunoassays

Three antisera raised against bovine serum albumin (BSA) conjugates of testosterone-3-(O-carboxy-methyl)-oxime (T-3-CMO), 11 beta-hydroxytestosterone-11-carboxymethyl ether (T-11 beta-O-CME) and 19-hydroxytestosterone-19-carboxymethyl-ether (T-19-O-CME) were evaluated in enzyme immunoassays (EIAs) in combinations with penicillinase-labeled T-3-CMO, T-11 beta-O-CME, T-19-O-CME, and testosterone-17 beta-hemisuccinate (T-17 beta-HS) for their influence on the sensitivity and specificity of EIAs. Of the various combinations, anti-T-3-CMO antiserum along with T-11 beta-O-CME-penicillinase showed no cross-reaction with any of the closely related steroids, although the same antibody had 21.6% binding to 5 alpha-dihydrotestosterone (5 alpha-DHT) in radioimmunoassay. All the homologous combinations appeared to be less sensitive due to their low affinity for testosterone. It was also apparent that of all the heterologous systems tested, only two combinations, (a) anti-T-19-O-CME antiserum and T-3-CMO-penicillinase and (b) anti-T-3-CMO antiserum and T-11 beta-O-CME-penicillinase, were found to be more sensitive. The former was less specific; it showed 70% cross-reaction with 5 alpha-DHT. The ability of testosterone to displace the hapten-enzyme conjugate and the specificity of the assay appear to depend on the position of the enzyme label on the steroid molecule as well as on the availability of antigenic sites in particular combinations of antibody and hapten-enzyme conjugates.

A practical large-scale synthesis of 17α-acetoxy-11β-(4-N,N-dimethylaminophenyl)-19-norpregna-4,9-diene-3,20-dione (CDB-2914) ☆

A new practical synthesis of 17α-acetoxy-11β-(4-N,N-dimethylaminophenyl)-19-norpregna-4,9-diene-3,20-dione (CDB-2914) is described. The synthesis gives easily isolable solids at all steps and is amenable to large-scale process.

Synthesis of a precursor for the preparation of 9α, 11α-tritiated 5α-androstane-3α,17β-diol 17-glucuronide

Starting from 11 beta-hydroxytestosterone, the synthesis of a strategic precursor, C-9 (11) unsaturated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide (9a), for the preparation of 9 alpha,11 alpha-tritiated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide has been achieved. The authors optimized the reaction conditions for catalytic reduction employing hydrogen and subsequent base hydrolysis followed by purification on Amberlite XAD-2 resin to obtain the saturated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide.

A new, practical synthesis of 2-methoxyestradiols.

An efficient and practical approach to synthesize moderate to large amounts of 2-methoxyestradiol (2-ME2) is described. The key step in the synthesis is the regioselective introduction of an acetyl group at the C-2 position of estradiol using a zirconium tetrachloride mediated Fries rearrangement carried out on estradiol diacetate. The seven step synthetic procedure readily gave 2-ME2 in 49% overall yield. Application of this method to the synthesis of 2-methoxy-7 alpha-methylestradiol is also described.

Tetrapropylammonium perruthenate as a mild and efficient oxidant for sensitive steroidal alcohols

Tetrapropylammonium perruthenate N-methylmorpholine N-oxide oxidation of steroidal alcohols is described. The reagent combination is mild and gave good yields of the corresponding ketones. Although the oxidation can generate ketones from 3-, 11-, 15-, 17-, and 20-hydroxy steroids, the oxidation of homoallylic alcohols proceeds in low yields. Finally, we observed that the oxidation reagents will convert 17 alpha-hydroxy-20-keto steroids to 17-keto systems in excellent yield.