title: Biological activities of 4-fluoro estrogen analogues.
abstract: As part of a study on the biological activity of gamma-emitting estradiol analogues, a series of fluorinated and/or brominated analogues of estradiol were synthesized. 4-Fluoro-1,3,5(10-estratrien-3,17 beta-diol (4-fluoro-estradiol) and 16 alpha-bromo-1,3,5(10)-estratrien-3,17 beta-diol (16 alpha-bromo-estradiol) had relative binding affinities (RBA) for the rabbit uterine cytosol receptor which were comparable to those of estradiol. However, while 4-fluoro-estradiol stimulated the increase in uterine weight of immature mice to the same amount as estradiol, 16 alpha-bromo-estradiol was less effective in this assay indicating that its metabolism is probably more rapid than that of estradiol. 16 beta-Bromo-1,3,5(10)-estratrien-3,17 beta-diol had a low RBA and was ineffective in stimulating uterine weight at the doses used. 4-Fluoro-16 alpha-bromo-estradiol had a lower RBA than either the 4-fluoro- or 16 alpha-bromo-estradiol and all the 4-fluoro-seleno-estrogens tested possessed low RBA's.
mesh_terms: D000818:Animals; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D051379:Mice; D009929:Organ Size / Q000187:drug effects; D011817:Rabbits; D011960:Receptors, Estrogen / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014599:Uterus / Q000187:drug effects / Q000502:physiology*
chemical_list: D011960:Receptors, Estrogen; D004958:Estradiol