title: Fucans from a Tunisian brown seaweed Cystoseira barbata: structural characteristics and antioxidant activity.
abstract: Sulfated polysaccharides from brown seaweeds are known to be a topic of numerous studies, due to their beneficial biological properties including antioxidant activity. Fucans were isolated from the brown seaweed Cystoseira barbata harvested in Tunisia. ATR-FTIR and (1)H-NMR spectroscopies demonstrated that C. barbata sulfated polysaccharides (CBSPs) consisted mainly of 3-linked-α-l-fucopyranosyl backbone, acetylated and mostly sulfated at C-4. Molar degrees of sulfation and acetylation of CBSPs were 0.79 and 0.27, respectively. Neutral sugars analysis determined by gas chromatography-mass spectrometry (GC-MS) showed that CBSPs were mainly composed of fucose (44.6%) and galactose (34.32%) with few amounts of other sugars such as glucose (7.55%), rhamnose (6.41%), xylose (4.21%) and mannose (2.91%). CBSPs were examined for in vitro antioxidant properties using various antioxidant assays. CBSPs exhibited important DPPH radical-scavenging activity (100% inhibition at a concentration of 1.5mg/ml) and considerable ferric reducing potential (24.62 mg ascorbic acid equivalents). Effective chelating activity and significant protection activity against hydroxyl radical induced DNA breakage were also recorded for CBSPs. However, in the linoleate-β-carotene system, CBSPs exerted moderate antioxidant activity (62% inhibition at a concentration of 1.5mg/ml). Therefore, CBSPs can be used as a potent natural antioxidant in food industry or in the pharmaceutical field.
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie, Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, B.P. 1173, 3038 Sfax, Tunisia. Electronic address: sabrine.sellimi@gmail.com.
authors.forename: Sabrine
authors.initials: S
authors.lastname: Sellimi
authors.affiliation: Laboratoire de Glycochimie et Reconnaissance Moléculaire, UMR 5032, Université Montpellier II, ENSCM, 8, rue de l'Ecole-Normale, 34296 Montpellier Cedex, France.
authors.forename: Nabil
authors.initials: N
authors.lastname: Kadri
authors.affiliation: Laboratoire de Glycochimie et Reconnaissance Moléculaire, UMR 5032, Université Montpellier II, ENSCM, 8, rue de l'Ecole-Normale, 34296 Montpellier Cedex, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Barragan-Montero
authors.affiliation: Laboratoire de Valorisation des Ressources Biologiques Naturelles, Faculté des Sciences Naturelles et de la Vie UFA, Sétif, Algeria.
authors.forename: Hocine
authors.initials: H
authors.lastname: Laouer
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie, Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hajji
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie, Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, B.P. 1173, 3038 Sfax, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D005643:Fucose / Q000737:chemistry / Q000494:pharmacology; D005690:Galactose / Q000737:chemistry / Q000494:pharmacology; D019787:Linoleic Acid / Q000378:metabolism; D000459:Phaeophyceae / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology*; D012624:Seaweed / Q000737:chemistry*; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D011134:Polysaccharides; D019207:beta Carotene; D005643:Fucose; C007789:fucoidan; D019787:Linoleic Acid; D005690:Galactose
keywords: (1)H-NMR; ATR-FTIR; Antioxidant activity; Cystoseira barbata; Fucans; GC–MS