title: [Conformation of the dienone system of delta 4,9-19-nor-3-ketosteroids from x-ray analysis data and its relation to reception and hormonal activity].
abstract: Basing on the data of the X-ray analysis of 2 beta-methylestr-4,9-dien-3-one-17 beta-ol (C19H26O2) and A-ring unsubstituted steroid 4,9-dien-3-ones, the noncomplanarity and flexibility of the conjugated dienone system in these transformed steroids has been demonstrated. The results have been also confirmed by UV spectroscopy. The ability of the dienone system to assume conformations with the out of- plane C3 = O3 and/or C9 = C10 bonds allows the AB-fragment of the steroid molecule to adopt the conformations required for interacting with various receptors. This property may also account for a simultaneous enhancement of several hormonal activities upon such a modification of steroids. The results of the X-ray analysis of 2 beta-methylestra-4,9-dien-3-one-17 beta-ol (space group P2(1)2(1)2(1), a 8,543(2), b 9,783(2), c 18,690(7) A, R 8,7%) are presented.
mesh_terms: D007664:Ketosteroids / Q000032:analysis* / Q000494:pharmacology; D008968:Molecular Conformation; D009277:Nandrolone / Q000031:analogs & derivatives* / Q000032:analysis / Q000494:pharmacology; D009654:Norsteroids / Q000032:analysis* / Q000494:pharmacology; D011987:Receptors, Steroid / Q000187:drug effects; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D007664:Ketosteroids; D009654:Norsteroids; D011987:Receptors, Steroid; C051222:2-methylestra-4,9-dien-3-one-17-ol; D009277:Nandrolone
vernacular_title: Konformatsiia dienonovoĭ sistemy delta 4,9-19-nor-3-ketosteroidov po dannym rentgenostrukturnogo analiza i ee sviaz' s retseptsieĭ i gormonal'noĭ aktivnost'iu.