Effective Inhibition of Hydroxyl Radicals by Hydroxylated Biphenyl Compounds

Abstract
In aqueous media, approximate rate constants for the reactions between hydroxyl radicals (•OH) and biphenyl compounds such as dehydrodieugenol, magnolol, honokiol, dehydrodidihydroeugenol, dehydrodivanillyl alcohol, and dehydrodicreosol were estimated by competition reactions for •OH between these biphenyls and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). By measuring the decrease in the height of the EPR signals of the .OH spin adduct, rate constants in the order of 109 to 1010 M were measured.