Identification of reaction products of (-)-epigallocatechin, (-)-epigallocatechin gallate and pyrogallol with 2,2-diphenyl-1-picrylhydrazyl radical

Catechins, the major constituents of tea, have been shown to have powerful antioxidant and antitumor activity. In this study, the radical scavenging behavior of catechins on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) was studied. Three reaction products of (-)-epigallocatechin, (-)-epigallocatechin gallate and pyrogallol with DPPH radical were purified and identified. This study provides some insight into the specific mechanism of the antioxidant reaction of catechins. A possible mechanism for the formation of reaction products is suggested.