title: Sterols from the Madagascar sponge Fascaplysinopsis sp.
abstract: The sponge Fascaplysinopsis sp. (order Dictyoceratida, Family Thorectidae) from the west coast of Madagascar (Indian Ocean) is a particularly rich source of bioactive nitrogenous macrolides. The previous studies on this organism led to the suggestion that the latter should originate from associated microsymbionts. In order to evaluate the influence of microsymbionts on lipid content, 10 samples of Fascaplysinopsis sp. were investigated for their sterol composition. Contrary to the secondary metabolites, the sterol patterns established were qualitatively and quantitatively stable: 14 sterols with different unsaturated nuclei, Δ(5), Δ(7) and Δ(5,7), were identified; the last ones being the main sterols of the investigated sponges. The chemotaxonomic significance of these results for the order Dictyoceratida is also discussed in the context of the literature. The conjugated diene system in Δ(5,7) sterols is known to be unstable and easily photo-oxidized during storage and/or experiments to produce 5α,8α-epidioxy sterols. However, in this study, no 5α,8α-epidioxysterols (or only trace amounts) were observed. Thus, it was supposed that photo-oxidation was avoided thanks to the natural antioxidants detected in Fascaplysinopsis sp. by both the DPPH and β-caroten bleaching assays.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Faculté des Sciences et Technologies, Université de la Réunion, 15 Avenue René Cassin, St Denis Messag Cedex 9, La Réunion, France. maurice.aknin@univ-reunion.fr
authors.forename: Maurice
authors.initials: M
authors.lastname: Aknin
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Gros
authors.forename: Jean
authors.initials: J
authors.lastname: Vacelet
authors.forename: Yoel
authors.initials: Y
authors.lastname: Kashman
authors.forename: Anne
authors.initials: A
authors.lastname: Gauvin-Bialecki
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D008055:Lipids / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification / Q000494:pharmacology; D018942:Macrolides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D008270:Madagascar; D009792:Oceans and Seas; D011161:Porifera / Q000737:chemistry* / Q000378:metabolism / Q000382:microbiology; D013261:Sterols / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification / Q000494:pharmacology; D013559:Symbiosis
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D008055:Lipids; D018942:Macrolides; D013261:Sterols