Studies on modified estrogens: towards the synthesis of novel 14,15-cyclopropa[a]estra-1,3,5(10),8-tetraenes.

To improve the ratio of non-hormonal to hormonal activity, estrogens 3 and 4 were modified at various molecule positions. Isomerization of the 14 alpha,15 alpha-methylene bridge, controlled 3-methoxy group cleavage with respect to the 14 alpha,15 alpha-methylene bridge stereochemistry, reduction of the 8-double bond, and substitution of the oxyfunctionality at C-17 by a methylene and a difluoromethylene moiety were in the focus. As a result of in vivo and in vitro tests, compounds 27 and 29 were selected as potential follow-up candidates of lead 3.

Nitrile hydratase from Rhodococcus erythropolis: metabolization of steroidal compounds with a nitrile group.

The progestin dienogest (17alpha-cyanomethyl-17beta-hydroxy-estra-4,9-dien-3-one) was metabolized by the nitrile hydratase-containing microorganism Rhodococcus erythropolis. An enzymatic hydrolysis of the nitrile group at the 17alpha-side chain was intended to obtain novel derivatives and to test them for progesterone receptor affinity. In contrast to the rapid enzymatic hydrolysis of nonsteroidal nitriles, the nitrile group of dienogest was cleaved very slowly. The dominant reaction was an aromatization of ring A. After prolonged fermentation, the 17alpha-acetamido derivatives of estradiol and of 9(11)-dehydroestradiol were formed. Three of the metabolites were also prepared synthetically. They were tested for hormonal activity by assessing their binding to progesterone and estrogen receptors in vitro. Neither the aromatized 17alpha-acetamido derivatives nor the dienogest derivative 17alpha-acetamido-17beta-hydroxy-estra-4,9-dien-3-one, which was prepared synthetically only, exhibited affinity for the progesterone receptor.

17Beta-hydroxy-11alpha-(3'-sulfanylpropyl)oxy-estra-1,3,5(10)- trien-3-yl sulfamate--a novel hapten structure: toward the development of a specific enzyme immunoassay (EIA) for estra-1,3,5(10)-triene-3-yl sulfamates.

The title compound 17 has been synthesized for the use as hapten in the development of a competitive enzyme immunoassay for estrogen sulfamates. The synthesis started from estradiol diacetate 2. Oxyfunctionalization at C-11 to give 11alpha-hydroxy steroid 8 was accomplished by hydroboration/alkaline hydrogen peroxide oxidation of the 9(11)-dehydro derivative 7, which was obtained from compound 2 via 9-hydroxylation with dimethyldioxirane. After transformation of compound 8 into the allyl ether 9, the side chain was thio-functionalized at the omega-position affording the thioate 11 in two steps. Selective silylether deprotection at position 3 followed by sulfamoylation gave the sulfamate 19, which in turn was demasked at position 17 and treated with sodium borohydride/aluminum chloride to liberate the side chain thiol. Alternatively, title compound 17 was synthesized via the disulfides 13-16. For the preparation of the immunogen the title compound 17 was coupled to bovine gamma globulin in a two-step procedure using an amine and thiol specific bifunctional crosslinker. The immunization of rabbits resulted in the formation of antibodies which clearly discriminated the sulfamoylated estrogens from the non-esterified estrogens. The use of a biotinylated hapten derivative as a tracer in combination with a streptavidin-peroxidase-tetramethylbenzidine based detection system allowed the measurement of estradiol 3-sulfamate (1) in the range of about 1 to 1000 pg/well.

Partial synthetic derivatization of canrenone and characterization of its impact on the inhibitory effect on Na+/K(+)-ATPase activity in human heart muscle.

To improve the weak inhibitory effect of 3-oxo-17 alpha-pregna-4,6-diene-21,17-carbolactone (canrenone, II) on Na+/K(+)-ATPase activity in human heart muscle, we have investigated the impact of hydrogenation, reduction, glycosidation, and the introduction of a 3-sulfonamido residue on the inhibitory potency of canrenone. The greatest increase in potency (> 20 times) was found for 3 beta-(alpha-L-rhamnopyranosyloxy)-5 beta, 17 alpha-pregnane-21, 17-carbolactone (IX). The 3-O-glycosides IX-XI are the first representatives of C/D-trans steroids with effector-receptor complex decay half-times longer than those of therapeutically used cardenolides.

The nitration of canrenone with acetic anhydride/nitric acid.

3-Oxo-17 alpha-pregna-4,6-diene-21,17-carbolactone (canrenone, II) is produced from the potassium salt of 17-hydroxy-3-oxo-17 alpha-pregna-4,6-diene-21-carboxylic acid (I) by acid catalyzed lactonization. II reacts with acetic anhydride/nitric acid to give one main product (III) and some minor products. The structure of III was determined by chemical and spectral analysis to the 4-nitro derivative of canrenone. This result is in contrast to the known reactions of II with most other reagents that were found to add at delta(6), and also in contrast to the reactions of acetic anhydride/nitric acid with alkenes. Electrophilic substitution at the ambident C4 is discussed as the reaction path. The 4-nitro group enhances the inhibitory activity of II against Na+/K(+)-ATPase, the target enzyme of the cardioactive digitalis glycosides, which appears to indicate increased cardioactivity.

Synthesis of estrogen sulfamates: compounds with a novel endocrinological profile.

Estrogen sulfamates are promising hormones by oral administration. Therefore, generally applicable and convenient methods for the multigram synthesis of these derivatives are desirable. Numerous estra-1,3,5(10)-trienes derived from estrone, estradiol. 14 alpha,15 alpha-methylenestradiol, ethinylestradiol, and estriol have been esterified with sulfamoyl chloride and N-methylsulfamoyl chloride by a novel approach involving the use of 2,6-di-tert-butylpyridines as bases and chemoselective hydroxy group protections. These pathways circumvent the nonselective formation of esters and side reactions by in situ generated azasulfenes. For toxicological and clinical studies a new synthesis of estrone sulfamate on a 100-g scale was developed using dimethylformamide as the solvent and base.

Ionic hydrogenation of 3-methoxy-14 alpha,15 alpha-methylenestra-1,3,5(10),8-tetraen-17 alpha-ol: a correction.

3-Methoxy-14 alpha,15 alpha-methylenestra-1,3,5(10),8-tetraen-17 alpha-ol on hydrogenation with triethylsilane/trifluoroacetic acid yielded 3-methoxy-14 beta,15 beta-methylenestra-1,3,5(10)-trien-17 alpha-ol, not the 14 alpha,15 alpha-methylene-9 beta product as previously described.

A novel synthesis of 14 alpha, 15 alpha-methylene estradiol (J 824).

A novel approach to the synthesis of the orally active estrogen 14 alpha,15 alpha-methylene estradiol (8, J 824) is described, starting with 3-methoxy-estra-1,3,5(10),8,14-pentaen-17 alpha-ol (5). The 14 alpha, 15 alpha-methylene bridge was sonochemically introduced by regioselective and stereoselective Simmons-Smith methylenation of the 14-double bond. Birch reduction of the 8-double bond provided the desired 8 beta-H, 9 alpha-H steroid, whereas ionic hydrogenation afforded the 8 beta-H, 9 beta-H isomer, together with an epimerization of the 17 alpha-hydroxy group. Oxidation of the Birch product yielded the corresponding 17-oxo steroid, which gave the title compound by diborane reduction. For radioimmunoassay development the 6-(O-carboxymethyl)-oximino derivative of 8 was prepared as hapten and the 2-hydroxy derivative of 8 was synthesized as a potential metabolite of 8, and 8 was tritium labeled as well.