title: Three new D-ring unsaturated sterols from the Mediterranean sponge Topsentia aurantiaca: structure determination and complete nuclear magnetic resonance assignment.
abstract: Three novel sterols with a rare D-ring unsaturation were isolated from the marine sponge Topsentia aurantiaca and identified as 5 alpha-cholest-14-ene-3 beta,16 alpha-diol (2), 24R-ethyl-5 alpha-cholest-14-ene-3 beta,16 alpha-diol (3), and 24S-ethyl-5 alpha-cholest-14-ene-3 beta,16 alpha-diol (4). The sponge also elaborates a further D-ring unsaturated sterol, 5 alpha-cholest-15-en-3 beta-ol (1), which has been previously described only as a synthetic product. All the 1H and 13C nuclear magnetic resonances of compounds 1 and 2 were assigned to the relevant protons and carbons by bidimensional COSY, HETCOR, and HMQC nuclear magnetic resonance experiments.
authors.affiliation: Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Ciminiello
authors.forename: E
authors.initials: E
authors.lastname: Fattorusso
authors.forename: S
authors.initials: S
authors.lastname: Magno
authors.forename: A
authors.initials: A
authors.lastname: Mangoni
authors.forename: M
authors.initials: M
authors.lastname: Pansini
mesh_terms: D002777:Cholestanols / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013261:Sterols / Q000737:chemistry*
chemical_list: D002777:Cholestanols; D013261:Sterols; C075394:cholest-14-ene-3,16-diol; C075395:24-ethylcholest-14-ene-3,16-diol