Abstract: Green Tea Polyphenols(GTP) consist of four components, EGCG(-)-epigallocatechin gallate, ECG(-)-epicatechin gallate, EGC(-)epigallocatechin, and EC(-)epicatechin, all of which have the structure of gallate group or pyrogallol group.In alkaline solution, they will be autooxidized to produce different semiquinone free radicals.We investigated the ESR spectroscopy of the pyrogallol GTP, and the four components of GTP respectively, analyzed the possible structure of responsible semiquinone free radical.The ESR signals of the four components are related to the simple unit of pyrogallol, and the ESR signals of GTP are related to their four components according to their respective quantity attribution.

Key words: Green tea polyphenols, Semiquinone free radicals, ESR spectroscopy