期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：1999
卷号：27
期号：2
页码：103-112
DOI：10.3164/jcbn.27.103
出版社：The Society for Free Radical Research Japan
摘要：To determine the peroxyl radical-scavenging activity of several biological substances, we developed a spin trapping assay using electron paramagnetic resonance (EPR). Peroxyl radicals, generated in a mixture of tert -butyl hydroperoxide and methemoglobin in sodium phosphate buffer, were trapped by 5, 5-dimethyl-1-pyrroline- N -oxide (DMPO). Scavenging activities were calculated from DMPO-OOR ( tert -butyl peroxyl radical spin adduct) signal by a kinetic competition study. The scavenging activity, R , of a given substance was expressed as the relative second-order rate constant of the reaction with peroxyl radical as compared with that obtained for DMPO. Of the various biological substances evaluated, ascorbic acid ( R =227), uric acid ( R =28), glutathione ( R =24), and α-tocopherol ( R =14) were major peroxyl radical scavengers in phosphate buffer. This method will be useful for determining peroxyl radical-scavenging activities of biological materials.
