title: Optimization of Pyrogallol Autoxidation Conditions and Its Application in Evaluation of Superoxide Anion Radical Scavenging Capacity for Four Antioxidants.
abstract: In this study, some factors influencing pyrogallol autoxidation, including EDTA, temperature, and solvent, were systematically investigated to improve its feasibility in the evaluation of antioxidants for the first time. Subsequently, the improved pyrogallol autoxidation conditions were used to assess the superoxide anion scavenging activity (SASA) of four commonly used antioxidants, namely, ascorbic acid, rutin, catechin, and gallic acid, by both the reaction rate method and the terminated method. The results indicate that pyrogallol autoxidation could be successfully used to determine the antioxidant capacity of ascorbic acid and rutin, which correspondingly suggests the feasibility of its use to measure the superoxide anion radical scavenging activity of polysaccharides and flavonols, because these compounds have a similar basic structural unit as ascorbic acid and rutin, respectively. Unexpectedly, however, pyrogallol autoxidation cannot be used to evaluate the SASA of catechin and gallic acid, although their good antioxidant capacity was confirmed by the 1,1-diphenyl-2-picrylhydrazyl assay. Together, these results suggest the importance of noting the conditions used for pyrogallol autoxidation when assessing the SASA of targeted compounds.
authors.affiliation: Shaanxi Normal University, School of Food Engineering and Nutrition Sciences, Xi'an, 710062 Shaanxi Province, People's Republic of China.
authors.forename: Qing-An
authors.initials: QA
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Song
authors.forename: Xue-Hui
authors.initials: XH
authors.lastname: Fan
authors.affiliation: Spanish National Research Council, Instituto de la Grasa, Ctra Utrera km 1, Campus Universidad Pablo de Olavide, 41013 Seville, Spain.
authors.forename: Juan Francisco
authors.initials: JF
authors.lastname: García Martín
mesh_terms: D000838:Anions / Q000032:analysis; D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis; D002392:Catechin / Q000032:analysis; D016166:Free Radical Scavengers / Q000032:analysis*; D005707:Gallic Acid / Q000032:analysis; D010084:Oxidation-Reduction; D011748:Pyrogallol / Q000737:chemistry*; D012431:Rutin / Q000032:analysis; D013481:Superoxides / Q000032:analysis*
chemical_list: D000838:Anions; D000975:Antioxidants; D016166:Free Radical Scavengers; D011748:Pyrogallol; D013481:Superoxides; D012431:Rutin; D005707:Gallic Acid; D002392:Catechin; D001205:Ascorbic Acid