title: Partial structural characterization and antioxidant activity of a phenolic-xylan from Castanea sativa hardwood.
abstract: 4-O-Methylglucuronoxylans (MGX) were isolated from chestnut wood sawdust using two different procedures: chlorite delignification followed by the classical alkaline extraction step, and an unusual green chemistry process of delignification using phthalocyanine/H2O2 followed by a simple extraction with hot water. Antioxidant properties of both MGX were evaluated against the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) by electronic spin resonance (ESR). IC50 of water-extracted MGX was found to be less than 225 μg mL(-1), in contrast with alkali-extracted MGX for which no radical scavenging was observed. Characterization of extracts by colorimetric assay, GC, LC-MS and NMR spectroscopy provided some clues to understanding structure-function relationships of MGX in connection with their antioxidant activity.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles (EA1069), Université de Limoges, Limoges, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Renault
authors.affiliation: Laboratoire de Chimie des Substances Naturelles (EA1069), Université de Limoges, Limoges, France.
authors.forename: Aline
authors.initials: A
authors.lastname: Barbat-Rogeon
authors.affiliation: Laboratoire de Chimie des Substances Naturelles (EA1069), Université de Limoges, Limoges, France. Electronic address: vincent.chaleix@unilim.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Chaleix
authors.affiliation: Laboratoire de Chimie des Substances Naturelles (EA1069), Université de Limoges, Limoges, France.
authors.forename: Claude-Alain
authors.initials: CA
authors.lastname: Calliste
authors.affiliation: Institut de Chimie Organique et Analytique (UMR7311), CNRS, Université d'Orléans, Orléans, France; Centre de Biophysique Moléculaire (UPR4301), CNRS, Université d'Orléans, Orléans, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Colas
authors.affiliation: Laboratoire de Chimie des Substances Naturelles (EA1069), Université de Limoges, Limoges, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gloaguen
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D029962:Fagaceae / Q000737:chemistry*; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D013329:Structure-Activity Relationship; D014934:Wood / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D014990:Xylans; C038910:glucuronoxylan; C044967:4-O-methyl glucuronoxylan
keywords: Antioxidant activity; Castanea sativa; Xylans