title: Conformational comparison of five follicular fluid meiosis-activating sterol-related active and inactive compounds.
abstract: The crystal structures of five follicular fluid meiosis-activating sterol-related Delta(8,14)-sterol compounds are presented. These are 4,4-dimethyl-23-phenyl-24-nor-5alpha-chola-8,14-dien-3beta-ol, C(31)H(44)O, 4,4-dimethyl-22-phenyl-23,24-dinor-5alpha-chola-8,14-dien-3beta-ol, C(30)H(42)O, (20R)-4,4-dimethyl-22-oxa-5alpha,20-cholesta-8,14,24-trien-3beta-ol, C(28)H(44)O(2), 4,4-dimethyl-23-phenyl-22-oxa-24-nor-5alpha-chola-8,14-dien-3beta-ol-water (4/1), 4C(30)H(42)O(2).H(2)O, and 4,4-dimethyl-5alpha-cholesta-8,14-dien-3-one, C(29)H(46)O. Two of the derivatives are inactive and three are active as agonists. Preliminary structure-activity relationship studies showed that the positions of the double bonds in the skeleton and the structures of the side chains are important determinants for activity. The conformations of the skeletons were compared with double-bond isomers retrieved from the Cambridge Structural Database [Allen & Kennard (1993). Chem. Des. Autom. News, 8, 1, 31-37]; no significant differences were found. Thus, conformational changes induced by the double bonds are not discriminative with respect to the activity of the compounds. Comparisons of the side-chain conformations of active and inactive structures revealed that the crystal structures were not conclusive as far as correlation of conformation and activity of the side chains were concerned.
authors.affiliation: Bijvoet Center for Biomolecular Research, Department of Crystal and Structural Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: D R
authors.initials: DR
authors.lastname: Boer
authors.forename: H
authors.initials: H
authors.lastname: Kooijman
authors.forename: M
authors.initials: M
authors.lastname: Groen
authors.forename: J
authors.initials: J
authors.lastname: van der Louw
authors.forename: J
authors.initials: J
authors.lastname: Kelder
authors.forename: J
authors.initials: J
authors.lastname: Kroon
mesh_terms: D018360:Crystallography, X-Ray; D005260:Female; D015571:Follicular Fluid / Q000166:cytology*; D006801:Humans; D006860:Hydrogen Bonding; D008540:Meiosis / Q000187:drug effects*; D008958:Models, Molecular; D008968:Molecular Conformation; D013261:Sterols / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D013261:Sterols