Hamada S, Kontani M, Hosono H, Ono H, Tanaka T, Ooshima T, Mitsunaga T, Abe I
Department of Oral Microbiology, Osaka University Faculty of Dentistry, Suita-Osaka, Japan.
FEMS Microbiol Lett. 1996 Sep 15;143(1):35-40. doi: 10.1111/j.1574-6968.1996.tb08458.x.
Oolong tea extract (OTE) and the purified polymeric polyphenols from OTE have been found to inhibit glucosyltransferase (GTase) of mutans streptococci. In view of the partial fermentation characteristic of oolong tea, we describe here an in vitro model reaction system to produce partially fermented products of D-(+)-catechin or green tea extract (GTE) using horseradish peroxidase. A dimeric catechin molecule was identified as dehydro-dicatechin A by instrumental analyses. The molecular size of some oligomeric catechins was estimated by the elution profile with HPLC. These catechin oligomers markedly inhibited GTase from Streptococcus sobrinus 6715. As the degree of polymerization of catechin or GTE increased, GTase was inhibited more effectively. These results suggest that polymeric polyphenols found in OTE are synthesized by partial fermentation due to oxidases/peroxidases present in tea leaves.
已发现乌龙茶提取物（OTE）和从OTE中纯化得到的聚合多酚可抑制变形链球菌的葡糖基转移酶（GTase）。鉴于乌龙茶的部分发酵特性，我们在此描述一种体外模型反应系统，该系统使用辣根过氧化物酶来制备D-(+)-儿茶素或绿茶提取物（GTE）的部分发酵产物。通过仪器分析鉴定出一种二聚体儿茶素分子为脱氢二儿茶素A。通过高效液相色谱（HPLC）的洗脱曲线估算了一些低聚儿茶素的分子大小。这些儿茶素低聚物显著抑制了远缘链球菌6715的GTase。随着儿茶素或GTE聚合度的增加，GTase受到的抑制作用更有效。这些结果表明，OTE中发现的聚合多酚是由于茶叶中存在的氧化酶/过氧化物酶导致部分发酵而合成的。
