Zhu N, Huang T C, Yu Y, LaVoie E J, Yang C S, Ho C T
Department of Food Science, Rutgers University, New Brunswick, New Jersey 08901-8520, USA.
J Agric Food Chem. 2000 Apr;48(4):979-81. doi: 10.1021/jf991188c.
(-)-Epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) are two important antioxidants in tea. They also display some antitumor activities, and these activities are believed to be mainly due to their antioxidative effects. However, the specific mechanisms of antioxidant action of tea catechins remain unclear. In this study are isolated and identified two novel reaction products of EGCG and one product of EGC when they were reacted separately with H(2)O(2). These products are formed by the oxidation and decarboxylation of the A ring in the catechin molecule. This study provides unequivocal proof that the A ring of EGCG and EGC may also be an antioxidant site. This study also indicates an additional reaction pathway for the oxidation chemistry of tea catechins.
（-）-表没食子儿茶素没食子酸酯（EGCG）和（-）-表没食子儿茶素（EGC）是茶叶中的两种重要抗氧化剂。它们还具有一些抗肿瘤活性，并且这些活性被认为主要归因于它们的抗氧化作用。然而，茶儿茶素抗氧化作用的具体机制仍不清楚。在本研究中，分离并鉴定了EGCG的两种新型反应产物和EGC与H₂O₂分别反应时的一种产物。这些产物是由儿茶素分子中A环的氧化和脱羧形成的。本研究提供了明确的证据，证明EGCG和EGC的A环也可能是一个抗氧化位点。本研究还表明了茶儿茶素氧化化学的另一条反应途径。
