title: Influence of the physico-chemical characteristics of chito-oligosaccharides (COS) on antioxidant activity.
abstract: Chito-oligosaccharides (COS) are being used as important functional materials for many applications due to their bioactivities. The aim of this research has been to assess the relationship between the physico-chemical characteristics, average molecular weight (Mw), acetylation degree (DA), polymerization degree (DP) and specially sequence composition determined by MALDI-TOF MS and the antioxidant properties of COS. These oligosaccharides were obtained by enzymatic depolymerization with chitosanase and lysozyme using a specific chitosan and its reacetylated product. The COS fraction below 5 kDa obtained from chitosanase depolymerization showed the highest capacity to scavenge DPPH radicals and to reduce Fe(3+). A correlation was found between the relative amount of molecules with a given A/D (acetylated vs deacetylated units) ratio within the COS and their antioxidant activity, which could be used to predict the antioxidant behavior of a fraction of chito-oligosaccharides.
authors.affiliation: Instituto de Estudios Biofuncionales, Dpto. Química Física II, Facultad de Farmacia, Universidad Complutense de Madrid, Pso. Juan XXIII, no. 1, 28040 Madrid, Spain.
authors.forename: Marian
authors.initials: M
authors.lastname: Mengíbar
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Mateos-Aparicio
authors.forename: Beatriz
authors.initials: B
authors.lastname: Miralles
authors.forename: Angeles
authors.initials: A
authors.lastname: Heras
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D055598:Chemical Phenomena; D002645:Chickens; D002839:Chromans / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D009113:Muramidase / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry / Q000494:pharmacology*; D033561:Penaeidae; D010851:Picrates / Q000378:metabolism; D058105:Polymerization / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D016166:Free Radical Scavengers; D009844:Oligosaccharides; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl; D006026:Glycoside Hydrolases; C019868:chitosanase; D009113:Muramidase; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid
keywords: Antioxidant activity; Chitosan; Chitosanase; Lysozyme; MALDI TOF mass spectrometry; Physico-chemical properties