title: Brown Algae (Phaeophyceae) from the Coast of Madagascar: preliminary Bioactivity Studies and Isolation of Natural Products.
abstract: Eight species of brown algae (Phaeophyceae) from the coast of Madagascar have been investigated for their chemical constituents. Fucosterol (3) was obtained as the most abundant compound. The brown alga Sargassum ilicifolium was the source for the first isolation of the terpenoid C27-alcohol 1,1',2-trinorsqualenol (1) from marine sources. From S. incisifolium we isolated the highly unsaturated glycolipid 1-O-palmitoyl-2-O-stearidonoyl-3-O-β-D-galactopyranosylglycerol (4) and we report the first full assignment of its (1)H and (13)C NMR data. Apo-9'-fucoxanthinone (8) along with 24-ketocholesterol (5), (22E)-3β-hydroxycholesta-5,22-dien-24-one (6), and saringosterol (7) were obtained from Turbinaria ornata. The crude extracts of all eight species of brown algae exhibited a pronounced antimicrobial activity against the Gram-positive bacteria Bacillus cereus, Staphylococcus aureus, and Streptococcus pneumoniae.
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany.
authors.forename: Marie Pascaline
authors.initials: MP
authors.lastname: Rahelivao
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany.
authors.forename: Margit
authors.initials: M
authors.lastname: Gruner
authors.affiliation: Centre National de Recherche sur l'Environnement, MESupRes, BP 1739, 101, Antananarivo, Madagascar.
authors.forename: Hanta
authors.initials: H
authors.lastname: Andriamanantoanina
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Bauer
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany. hans-joachim.knoelker@tu-dresden.de.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Knölker
keywords: Antimicrobial activity; Brown algae; NMR spectroscopy; Steroids; Terpenoids