title: Conformational study of the cembranoid sarcophytol A, a potent anti-tumor-promoter.
abstract: Conformational analysis of the marine cembranoid sarcophytol A (1a), a potent anti-tumor promoter, was carried out using a newly introduced molecular mechanic and molecular dynamic program Discover. Four minimum-energy conformations were derived, in accordance with a previous results of the epoxidation of 1a, which afforded 7R,8R/7S,8S- and 11R,12R/11S,12S-epoxide pairs. The most stable conformation was the one having C-19 and C-20 directed opposite to C-18, with respect to the average plane of the fourteen-membered ring. X-Ray crystallography of sarcophytol A alpha-methoxy-alpha-trifluoromethylphenylacetate (1c) was carried out simultaneously. This confirmed the 14S absolute configuration of 1a but the conformation of crystalline 1c did not correspond to any of the four minimum-energy conformers of 1a.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Nomura
authors.forename: H
authors.initials: H
authors.lastname: Munakata
mesh_terms: D003460:Crystallization; D004224:Diterpenes / Q000032:analysis*; D008956:Models, Chemical; D008968:Molecular Conformation; D014961:X-Ray Diffraction
chemical_list: D004224:Diterpenes; C058761:sarcophytol A