title: Antioxidant activities of a polyglucuronic acid sodium salt obtained from TEMPO-mediated oxidation of xanthan.
abstract: A xanthouronic acid sodium salt called xanthouronan was produced from xanthan by regioselective oxidation with NaOCl/NaBr using 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) as catalyst. The efficiency of the one pot TEMPO-mediated oxidation was confirmed by HPAEC-PAD, (13)C NMR, and FT-IR. The oxidation degree was close to 98% and the mass yield of this new polyglucuronic acid was higher than 90% (w/w). The macromolecular characterization of xanthouronan using SEC-MALLS showed a molecular size reduced by a third due to the oxidation treatment and the degree of polymerization (DP) of the xanthouronan form was about 665. The evaluation of the enzymatic degradation of this C-6 carboxylated xanthan by various polysaccharide hydrolases and one polysaccharide lyase showed its high resistant to biodegradation. The antioxidant activity of xanthouronan was also tested by using the 2,2'-diphenyl-1-picrylhydrazyle (DPPH) and hydroxyl radical procedures. At 1 g/L, xanthouronan presented 75% of the ascorbic acid antioxidant activity.
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut Pascal, UMR 6602 CNRS Polytech Clermont-Ferrand, 24 avenue des Landais, BP 206, Aubière Cedex F-63174, France. Electronic address: cedric.delattre@univ-bpclermont.fr.
authors.forename: C
authors.initials: C
authors.lastname: Delattre
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut Pascal, UMR 6602 CNRS Polytech Clermont-Ferrand, 24 avenue des Landais, BP 206, Aubière Cedex F-63174, France.
authors.forename: G
authors.initials: G
authors.lastname: Pierre
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut Pascal, UMR 6602 CNRS Polytech Clermont-Ferrand, 24 avenue des Landais, BP 206, Aubière Cedex F-63174, France.
authors.forename: C
authors.initials: C
authors.lastname: Gardarin
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 80026, Aubière Cedex F-63171, France.
authors.forename: M
authors.initials: M
authors.lastname: Traikia
authors.affiliation: Laboratoire des Polysaccharides Microbiens et Végétaux, IUT d'Amiens, Avenue des Facultés, Le Bailly, Amiens Cedex F-80025, France.
authors.forename: R
authors.initials: R
authors.lastname: Elboutachfaiti
authors.affiliation: Graduate School of Agricultural and Life Science, Biomaterial Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 133-8657, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Isogai
authors.affiliation: Clermont Université, Université Blaise Pascal, Institut Pascal, UMR 6602 CNRS Polytech Clermont-Ferrand, 24 avenue des Landais, BP 206, Aubière Cedex F-63174, France.
authors.forename: P
authors.initials: P
authors.lastname: Michaud
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D003497:Cyclic N-Oxides / Q000737:chemistry*; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D011134:Polysaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D012973:Sodium Hypochlorite / Q000737:chemistry; D014574:Uronic Acids / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D001965:Bromides; D003497:Cyclic N-Oxides; D010851:Picrates; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D017670:Sodium Compounds; D014574:Uronic Acids; C000602707:xanthouronan; D012972:Sodium Hydroxide; C004931:1,1-diphenyl-2-picrylhydrazyl; D012973:Sodium Hypochlorite; C027938:sodium bromide; C002563:xanthan gum; C003959:TEMPO
keywords: Antioxidant activity; Polyglucuronic acid; TEMPO oxidation; Xanthan; Xanthouronic acid