title: New method to determine antioxidant activity of polyphenols.
abstract: The capacity of polyphenolic compounds to reduce the beta-carotene-linoleic acid cooxidation enzymatically induced by soybean lipoxygenase was assayed to determine their comprehensive antioxidant ability. The inhibition of the coupled oxidation is a well-known spectrophotometric method for the antioxidant activity measurement. A modification of this method is proposed to reduce assay time and to gain simplicity. The antioxidant abilities of several polyphenols were determined, and quercetin and sinapic acid were most active. These results were compared to those obtained by the DPPH* procedure to evaluate the free radical scavenging contribution to the total protective action. The highest values of antiradical activity were found for ellagic and quercetin.
authors.affiliation: Instituto de Ciencias Químicas, Facultad de Agronomía y Agroindustrias, Universidad Nacional de Santiago del Estero, Avda. Belgrano (S) 1912 (4200), Santiago del Estero, Argentina.
authors.forename: Lucrecia L
authors.initials: LL
authors.lastname: Chaillou
authors.forename: Mónica A
authors.initials: MA
authors.lastname: Nazareno
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D001713:Biphenyl Compounds; D005419:Flavonoids / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D007700:Kinetics; D019787:Linoleic Acid / Q000737:chemistry / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D010851:Picrates / Q000737:chemistry; D059808:Polyphenols; D012996:Solutions; D013057:Spectrum Analysis; D019207:beta Carotene / Q000737:chemistry / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D005609:Free Radicals; D010636:Phenols; D010851:Picrates; D059808:Polyphenols; D012996:Solutions; D019207:beta Carotene; D019787:Linoleic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D008084:Lipoxygenase