title: Steroidal glycosides from the marine sponge Pandaros acanthifolium.
abstract: The chemical composition of the Caribbean sponge Pandaros acanthifolium was investigated and led to the isolation of seven new steroidal glycosides namely pandarosides A-D (1, 3, 4 and 6) along with the three methyl esters of pandarosides A, C, and D (2, 5 and 7). Their structures were characterized as 3beta-[beta-glucopyranosyl-(1-->2)-beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-poriferast-16-ene-15,23-dione (1) and its methyl ester (2), 3beta-[beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-poriferast-16-ene-15,23-dione (3), 3beta-[beta-glucopyranosyl-(1-->2)-beta-glucopyranosyloxyuronic acid]-16-hydroxy-5alpha,14beta-cholest-16-ene-15,23-dione (4) and its methyl ester (5), 3beta-(beta-glucopyranosyloxyuronic acid)-16-hydroxy-5alpha,14beta-cholest-16-ene-15,23-dione (6) and its methyl ester (7) on the basis of detailed spectroscopic analyses, including 2D NMR and HRESIMS studies. Pandarosides A-D and their methyl esters (1-7) are all characterized by a rare 2-hydroxycyclopentenone D-ring with a 14beta configuration. The absolute configuration of the aglycon part of pandaroside A (1) was assigned by comparison between experimental and TDDFT calculated circular dichroism spectra on the more stable conformer.
authors.affiliation: Laboratoire de Chimie des Molécules Bioactives et des Arômes UMR 6001 CNRS, University of Nice-Sophia Antipolis, Faculté des Sciences Parc Valrose, 06108 Nice Cedex 2, France.
authors.forename: Nadja
authors.initials: N
authors.lastname: Cachet
authors.forename: Erik L
authors.initials: EL
authors.lastname: Regalado
authors.forename: Grégory
authors.initials: G
authors.lastname: Genta-Jouve
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mehiri
authors.forename: Philippe
authors.initials: P
authors.lastname: Amade
authors.forename: Olivier P
authors.initials: OP
authors.lastname: Thomas
mesh_terms: D000818:Animals; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D011161:Porifera / Q000737:chemistry*; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D006027:Glycosides; D013256:Steroids