title: Ophirasterol, a new C31 sterol from the marine sponge Topsentia ophiraphidites.
abstract: Analysis of the sterol fraction obtained from the Colombian Caribbean sponge Topsentia ophiraphidites revealed that this sponge is a rich source of C30 and C31 sterols. Among them, a new C31 sterol, named ophirasterol, was isolated, and its structure was established as (22E,24R)-24-(1-buten-2-yl)cholesta-5,22-dien-3beta-ol (1) by spectral means and comparison with synthetic C-24 epimers with known configuration. Other isolated C30 and C31 sterols were the known 24-ethyl-24-methyl-22-dehydrocholesterol (2), 24-isopropyl-22-dehydrocholesterol (3), 24-isopropylcholesterol (4), 24-ethyl-24-methylcholesterol (5), 24-isopropenyl-25-methyl-22-dehydrocholesterol (6) and 24-isopropenyl-25-methylcholesterol (7), and 24-isopropenyl-22-dehydrocholesterol (8).
authors.affiliation: Departamento de Química, Universidad Nacional de Colombia, Ciudad Universitaria, AA 14490, Bogotá, Colombia.
authors.forename: Gladys J
authors.initials: GJ
authors.lastname: Calderón
authors.forename: Leonardo
authors.initials: L
authors.lastname: Castellanos
authors.forename: Carmenza
authors.initials: C
authors.lastname: Duque
authors.forename: Shizue
authors.initials: S
authors.lastname: Echigo
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hara
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimoto
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011161:Porifera / Q000737:chemistry*; D013237:Stereoisomerism; D013261:Sterols / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D013261:Sterols; C492803:ophirasterol; D002784:Cholesterol