中文摘要：

Theaflavins (TF ) 是几 epimerized catechins 的 dimers，它特殊在红茶发酵期间被形成。在清除在四主要 TF 衍生物( theaflavin ( TF1 )， theaflavin-3-gallate ( TF2A )， theaflavin-3-gallate ( TF2B )，和 theaflavin-3,3-digallate ( TF3 ))之中探索差别在 vitro 的反应的氧种类( ROS )，他们禁止 superoxide 的性质，汗衫氧，氢过氧化物，并且氢氧根上的氢氧根激进分子，和他们的效果导致激进分子的 DNA 氧化损坏系统地在现在的学习被分析。结果显示出那，与相比()-epigallocatechin gallate (EGCG ) ， TF 衍生物是为清除的好抗氧化剂 ROS 并且阻止氢氧根在 vitro 的导致激进分子的 DNA 损坏。TF3 在清除是最积极的氢过氧化物和氢氧根基，和 TF1 压制了 superoxide。在 vitro 的导致激进分子的 DNA 损坏被发现的汗衫氧，氢过氧化物，氢氧根基，和氢氧根上的 TF2B 的积极抗氧化剂能力。在与他们的化学结构的关系的四主要 TF 衍生物的抗氧化剂能力之间的差别也被讨论。我们建议在 TF 衍生物之中的这些活动差别将是有益的清除有治疗学的潜力的不同 ROS。

英文摘要：

Theaflavins（TFs） are the dimers of a couple of epimerized catechins,which are specially formed during black tea fermentation.To explore the differences among four main TF derivatives（theaflavin（TF 1）,theaflavin3-gallate（TF 2 A）,theaflavin-3＇-gallate（TF 2 B）,and theaflavin-3,3＇-digallate（TF 3）） in scavenging reactive oxygen species（ROS） in vitro,their properties of inhibiting superoxide,singlet oxygen,hydrogen peroxide,and the hydroxyl radical,and their effects on hydroxyl radical-induced DNA oxidative damage were systematically analyzed in the present study.The results show that,compared with（）-epigallocatechin gallate（EGCG）,TF derivatives were good antioxidants for scavenging ROS and preventing the hydroxyl radical-induced DNA damage in vitro.TF 3 was the most positive in scavenging hydrogen peroxide and hydroxyl radical,and TF 1 suppressed superoxide.Positive antioxidant capacities of TF 2 B on singlet oxygen,hydrogen peroxide,hydroxyl radical,and the hydroxyl radical-induced DNA damage in vitro were found.The differences between the antioxidant capacities of four main TF derivatives in relation to their chemical structures were also discussed.We suggest that these activity differences among TF derivatives would be beneficial to scavenge different ROS with therapeutic potential.