title: Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate.
abstract: The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.
authors.affiliation: Gedeon Richter Ltd., Department of Steroid Research, P.O. Box 27, 1475, Budapest, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Tuba
authors.forename: C W
authors.initials: CW
authors.lastname: Bardin
authors.forename: A
authors.initials: A
authors.lastname: Dancsi
authors.forename: E
authors.initials: E
authors.lastname: Francsics-Czinege
authors.forename: C
authors.initials: C
authors.lastname: Molnár
authors.forename: J
authors.initials: J
authors.lastname: Csörgei
authors.forename: G
authors.initials: G
authors.lastname: Falkay
authors.forename: S S
authors.initials: SS
authors.lastname: Koide
authors.forename: N
authors.initials: N
authors.lastname: Kumar
authors.forename: K
authors.initials: K
authors.lastname: Sundaram
authors.forename: V
authors.initials: V
authors.lastname: Dukát-Abrók
authors.forename: G
authors.initials: G
authors.lastname: Balogh
mesh_terms: D000818:Animals; D001681:Biological Assay; D003271:Contraceptive Agents, Female / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000187:drug effects; D005260:Female; D016912:Levonorgestrel / Q000494:pharmacology; D008297:Male; D009653:Norprogesterones / Q000138:chemical synthesis* / Q000494:pharmacology*; D011247:Pregnancy; D011255:Pregnancy Maintenance / Q000187:drug effects; D011374:Progesterone / Q000031:analogs & derivatives / Q000494:pharmacology; D045167:Progesterone Congeners / Q000138:chemical synthesis / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C408943:16-methylene-17-hydroxy-18-methyl-19-norpregn-4-ene-3,20-dione acetate; D003271:Contraceptive Agents, Female; D009653:Norprogesterones; D045167:Progesterone Congeners; D011374:Progesterone; D016912:Levonorgestrel; C029167:ST 1435