Epitheaflagallin (ETFG) and epitheaflagallin 3-O-gallate (ETFGg) are minor polyphenols in black tea extract that are enzymatically synthesized from epigallocatechin (EGC) and epigallocatechin gallate (EGCg), respectively, in green tea extract via laccase oxidation in the presence of gallic acid. The constituents of laccase-treated green tea extract in the presence of gallic acid are thus quite different from those of nonlaccase-treated green tea extract: EGC and EGCg are present in lower concentrations, and ETFG and ETFGg are present in higher concentrations. Additionally, laccase-treated green tea extract contains further polymerized catechin derivatives, comparable with naturally fermented teas such as oolong tea and black tea. We found that ETFGg and laccase-treated green tea extracts exhibit versatile physiological functions in vivo and in vitro, including antioxidative activity, pancreatic lipase inhibition, Streptococcus sorbinus glycosyltransferase inhibition, and an inhibiting effect on the activity of matrix metalloprotease-1 and -3 and their synthesis by human gingival fibroblasts. We confirmed that these inhibitory effects of ETFGg in vitro match well with the results obtained by docking simulations of the compounds with their target enzymes or noncatalytic protein. Thus, ETFGg and laccase-treated green tea extracts containing ETFGg are promising functional food materials with potential antiobesity and antiperiodontal disease activities.

中文翻译：

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没食子酸存在下经漆酶处理的绿茶提取物中生成的表皮鞭毛蛋白3- O-加仑酯的功能表征

上皮鞭毛蛋白（ETFG）和上皮鞭毛蛋白3- Oβ-没食子酸酯（ETFGg）是红茶提取物中的次要多酚，它们是通过在没食子酸存在下通过漆酶氧化在绿茶提取物中通过表没食子儿茶素（EGC）和表没食子儿茶素没食子酸酯（EGCg）酶法合成的。因此，在没食子酸存在下，经漆酶处理的绿茶提取物的成分与未经漆酶处理的绿茶提取物的成分完全不同：EGC和EGCg的浓度较低，而ETFG和ETFGg的浓度较高。另外，经漆酶处理的绿茶提取物还含有其他聚合的儿茶素衍生物，与天然发酵茶（如乌龙茶和红茶）相当。我们发现ETFGg和漆酶处理的绿茶提取物在体内和体外均具有多种生理功能，包括抗氧化活性，山梨链球菌糖基转移酶的抑制作用，对基质金属蛋白酶-1和-3的活性以及人牙龈成纤维细胞合成的抑制作用。我们证实，ETFGg的这些体外抑制作用与通过将化合物与目标酶或非催化蛋白对接模拟获得的结果非常吻合。因此，ETFGg和含ETFGg的经漆酶处理的绿茶提取物是具有潜在的抗肥胖和抗牙周疾病活性的有前途的功能性食品材料。