title: Synthesis and pharmacological evaluation of new 16-methyl pregnane derivatives.
abstract: The pharmacological activity of several new pregnane derivatives 15-19 were determined on gonadectomized male hamster flank organs, seminal vesicles and in vitro conversion of testosterone (T) to dihydrotestosterone (DHT) as 5alpha-reductase inhibitors. Steroids 15-19 decreased the diameter of the pigmented spot in the flank organs as compared to the T treated animals; in this model, steroids 16 and 19 showed a higher activity than the commercially available finasteride 3. Injection of T increased the weight of the seminal vesicles. Compounds 15-19 when injected together with T decreased the weight of the seminal vesicles thus showing an antiandrogenic effect. The trienone 19 exhibited a considerably higher activity than finasteride. Steroids 15-19 inhibited the in vitro metabolism of [3H]T to [3H]DHT in seminal vesicles homogenates of gonadectomized male hamsters. Compounds 18 and 19 showed a much higher antiandrogenic effect than finasteride. This enhancement of the biological activity could probably be attributed to the coplanarity of the steroidal skeleton as previously observed by our group. The high antiandrogenic activity of the epoxy compound 16 is probably the result of the ring opening of the oxiran ring with the nucleophilic part of the enzyme 5alpha-reductase thus leading to a stable adduct with concomitant deactivation of this enzyme.
authors.affiliation: Department of Pharmacy, Faculty of Chemistry, UNAM Ciudad Universitaria, Mexico DF, Mexico.
authors.forename: Elena
authors.initials: E
authors.lastname: Ramirez
authors.forename: Marisa
authors.initials: M
authors.lastname: Cabeza
authors.forename: Ivonne
authors.initials: I
authors.lastname: Heuze
authors.forename: Edgar
authors.initials: E
authors.lastname: Gutiérrez
authors.forename: Eugene
authors.initials: E
authors.lastname: Bratoeff
authors.forename: Marisol
authors.initials: M
authors.lastname: Membrillo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Lira
mesh_terms: D058891:5-alpha Reductase Inhibitors; D000726:Androgen Antagonists / Q000138:chemical synthesis* / Q000494:pharmacology; D000818:Animals; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D008297:Male; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D011278:Pregnanes / Q000138:chemical synthesis* / Q000494:pharmacology; D012669:Seminal Vesicles / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism
chemical_list: D058891:5-alpha Reductase Inhibitors; D000726:Androgen Antagonists; D004791:Enzyme Inhibitors; D011278:Pregnanes; D013739:Testosterone