Steroidal glycosides from the marine sponge Pandaros acanthifolium.
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.
Cachet
Nadja
N
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.
Regalado
Erik L
EL
Genta-Jouve
Grégory
G
Mehiri
Mohamed
M
Amade
Philippe
P
Thomas
Olivier P
OP
D000818:Animals; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D011161:Porifera / Q000737:chemistry*; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification*
D006027:Glycosides; D013256:Steroids