“… p-chlorophenol … GSH to generate a large amount of superoxide radical (O2*-) or glutathione thiyl radical (GS*), while, phenolic compounds such as quercetin and Trolox C … generation of O2*- and GS*, their quenching activities for a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), were investigated by ESR spectroscopy.”