Appl Environ Microbiol. 1995 Jul;61(7):2768-70. doi: 10.1128/aem.61.7.2768-2770.1995.
We previously showed that the polymeric forms of polyphenols present in oolong tea extract exhibited strong inhibitory activities against glucosyltransferases (GTases) of mutans streptococci, while green tea extract, which is rich in catechins, did not show such GTase-inhibitory activities. In this study, (+)-catechin [2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol] was found to be glucosylated by the GTase of Streptococcus sobrinus 6715 with sucrose as the substrate, and the product was identified as 4(prm1)-O-(alpha)-d-glucopyranosyl-(+)-catechin, with a molecular weight of 452. The (alpha)-glucosylated (+)-catechin did not exhibit significant inhibition of glucan synthesis from sucrose by the GTase, which is in contrast to the polymeric polyphenols isolated from oolong tea leaves.
我们之前的研究表明，乌龙茶提取物中的多酚聚合形式对变形链球菌的葡糖基转移酶（GTases）表现出强烈的抑制活性，而富含儿茶素的绿茶提取物则没有表现出这种 GTase 抑制活性。在这项研究中，（+）-儿茶素[2-（3,4-二羟基苯基）-3,4-二氢-2H-1-苯并吡喃-3,5,7-三醇]被发现可与蔗糖作为底物被变形链球菌 6715 的 GTase 葡糖基化，产物被鉴定为 4(prm1)-O-(alpha)-d-葡萄糖基-（+）-儿茶素，分子量为 452。（alpha）-葡糖基化（+）-儿茶素对 GTase 催化蔗糖合成葡聚糖的抑制作用不明显，这与从乌龙茶叶片中分离得到的聚合多酚不同。
