ACTION OF PHENOLIC ANTIOXIDANTS ON VARIOUS ACTIVE OXYGEN SPECIES

The action of phenolic antioxidants. such as probucol, on various acti ve oxygen species was investigated using luminol chemiluminescence and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The vario us active oxygen species, including hydroxyl radicals(Fenton reaction) , superoxide anions, singlet oxygen and hypochlorite ions were examine d with phenolic antioxidants under aqueous and nonaqueous conditions. Probucol showed a quenching effect on both superoxide anions and hypoc hlorite ions in nonaqueous solution. However, it had no effect on hydr oxyl radicals. a-Tocopherol, a natural phenolic antioxidant. showed a stronger quenching effect on superoxide anions and hypochlorite ions t han probucol, and quenched hydroxyl radicals in nonaqueous solution. F urthermore, Trolox showed a quenching effect on all active oxygen spec ies in both aqueous and nonaqueous solution. The antioxidants were stu died under comparable conditions in a series of test systems and the r eactivity profiles depicted as 'radar charts' which are helpful for ch aracterizing antioxidant action.