Chung Joo Eun, Kurisawa Motoichi, Kim Young-Jin, Uyama Hiroshi, Kobayashi Shiro
Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, 615-8510, Japan.
Biomacromolecules. 2004 Jan-Feb;5(1):113-8. doi: 10.1021/bm0342436.
Catechin exhibits numerous biological and pharmacological effects attributed to antioxidant action. The synthetic poly(catechin)s condensed through acetaldehyde with different molecular weights were assessed in terms of antioxidant activity and enzyme inhibitory activity on the basis of a catechin repeating unit and compared with monomeric catechin. The poly(catechin)s showed great amplification of superoxide scavenging activity, xanthine oxidase (XO) inhibitory activity, and inhibition effects on human low-density lipoprotein oxidation initiated by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) as a radical generator on the catechin unit level, compared to monomeric catechin: these activities were proportional to their molecular weights. The reducing power of the polymer was lower than that of monomeric catechin, which decreased with increasing the molecular weight. The polymer also protected endothelial cells from oxidative injury induced by AAPH, with a greater effect expressed on a catechin unit basis than that of the monomer. These results demonstrate that the poly(catechin)s are more potent antioxidant agents and enzyme inhibitors.
儿茶素具有多种归因于抗氧化作用的生物学和药理学效应。基于儿茶素重复单元，对通过乙醛缩合得到的不同分子量的合成聚儿茶素的抗氧化活性和酶抑制活性进行了评估，并与单体儿茶素进行了比较。与单体儿茶素相比，聚儿茶素在儿茶素单元水平上表现出超氧化物清除活性、黄嘌呤氧化酶（XO）抑制活性以及对由2,2'-偶氮二异丁脒盐酸盐（AAPH）作为自由基引发剂引发的人低密度脂蛋白氧化的抑制作用的极大增强：这些活性与它们的分子量成正比。聚合物的还原能力低于单体儿茶素，且随着分子量的增加而降低。该聚合物还保护内皮细胞免受AAPH诱导的氧化损伤，以儿茶素单元为基础表现出比单体更大的效果。这些结果表明聚儿茶素是更有效的抗氧化剂和酶抑制剂。
