Evaluation of free radical scavenging activities of antioxidants with an H2O2/NaOH/DMSO system by electron spin resonance

An H2O2/NaOH/DMSO system has been developed for the formation of three free radicals, and the application of the system was examined with the antioxid ants ascorbic acid and tocopherol. Superoxide anion, hydroxyl radical,and m ethyl radical are simultaneously generated in this system. The scavenging a ctivity of ascorbic acid and tocopherol for these radicals was estimated by 5,5'-dimethyl-1-pyrroline-N-oxide spin trapping electron spin resonance. B oth water-soluble and oil-soluble antioxidants could be evaluated by using this system. Ascorbic acid specifically inhibited the superoxide anion and hydroxyl radical, whereas tocopherol suppressed the methyl radical.