title: Structure-activity relationships of 9 beta-estrogens.
abstract: The 9 beta isomers of estradiol-17 beta, estradiol-17 a estrone and 17-ethinylestradiol-17 beta were synthesized and compared with their 9a-counterparts in the rat uterine cytosol estrogen receptor, uterotropic, and gonadotropin release inhibition assays. Except for 17-ethinyl-9 beta-estradiol-17 beta which was as active as its 9a isomer in the uterotropic assay, none of the 9 beta estrogens exhibited any biological activity which was equal to or greater than their 9a counterparts. For examples, 9 beta-estradiol-17 beta was 1/10 as active as estradiol-17 beta, and 9 beta-estrone was 1/4 as active as estrone in the uterotropic assay.
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology; D045166:Estradiol Congeners / Q000494:pharmacology*; D004970:Estrone / Q000494:pharmacology; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D006062:Gonadotropins / Q000378:metabolism; D066298:In Vitro Techniques; D051381:Rats; D011960:Receptors, Estrogen / Q000187:drug effects; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014599:Uterus / Q000187:drug effects
chemical_list: D045166:Estradiol Congeners; D006062:Gonadotropins; D011960:Receptors, Estrogen; D004970:Estrone; D004997:Ethinyl Estradiol; D004958:Estradiol