title: 17alpha-Ethyl-20alpha-and -20beta-dihydroprogesterones and other 17alpha-ethyl-substituted pregnanes as potential contragestational agents.
abstract: The 17alpha-ethyl-substituted analogs of the two epimeric 20-dihydroprogesterones, allopregnadedione and pregn-5-ene-3,20-dione, were synthesized and evaluated for their possible oral contragestational (postcoital antifertility) activity in the rat. The compounds, though bound strongly to the progesterone receptor in vitro, were inactive preimplantively at 10 mg/kg and postimplantively at 40 mg/kg in vivo.
mesh_terms: D004092:20-alpha-Dihydroprogesterone / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D003281:Contraceptives, Postcoital / Q000138:chemical synthesis*; D003283:Contraceptives, Postcoital, Synthetic / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D010064:Embryo Implantation / Q000187:drug effects; D005260:Female; D005298:Fertility / Q000187:drug effects; D005865:Gestational Age; D011278:Pregnanes / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D011374:Progesterone / Q000031:analogs & derivatives*; D051381:Rats; D011956:Receptors, Cell Surface; D013237:Stereoisomerism
chemical_list: D003281:Contraceptives, Postcoital; D003283:Contraceptives, Postcoital, Synthetic; D011278:Pregnanes; D011956:Receptors, Cell Surface; D004092:20-alpha-Dihydroprogesterone; D011374:Progesterone