title: Effect of carboxymethylation on antioxidant properties and radical degradation of mannans and glucans.
abstract: Carboxymethyl derivatives (CM-derivatives) of α,β-mannans from yeasts, Saccharomyces cerevisiae β-glucan and dextran (α-glucan) were found to possess strong antioxidant activities against reactive hydroxyl radicals (OH*) compared to underivatized polysaccharides. When CM-derivatives having similar DS (0.41-0.45) were compared, the antioxidant activity decreased in order CM-mannan>CM-β-glucan>CM-dextran. Moreover, the antioxidant activities against OH* increased with increasing degree of substitution (DS) of polysaccharides. The CM-mannan and CM-dextran with the highest DS (0.73 and 1.1, respectively) were the strongest antioxidants and their degradation by OH* decreased with increased carboxymethylation. The scavenging abilities of CM-polysaccharides against stable DPPH radical (DPPH) were lower than those of original underivatized ones. Also this scavenging property against DPPH was lower compared to antioxidant effect against OH*.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovak Republic. Electronic address: chememch@savba.sk.
authors.forename: Eva
authors.initials: E
authors.lastname: Machová
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovak Republic.
authors.forename: Alžbeta
authors.initials: A
authors.lastname: Čížová
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovak Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Bystrický
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002175:Candida / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D005936:Glucans / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000378:metabolism; D007502:Iron Chelating Agents / Q000737:chemistry / Q000494:pharmacology; D008351:Mannans / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D005936:Glucans; D007502:Iron Chelating Agents; D008351:Mannans; D017665:Hydroxyl Radical
keywords: Antioxidant activity; Carboxymethyl polysaccharides; Degradation by OH