Enzymatic preparation of kaempferol from green tea seed and its antioxidant activity
Enzymatic preparation of kaempferol from green tea seed and its antioxidant activity
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DOI：
10.1021/jf052900a
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发表时间：
2006-04-19
影响因子：
6.1
通讯作者：
Chang, IS
中科院分区：
文献类型：
--
作者：
Park, JS;Rho, HS;Chang, IS
在绿色茶中的黄酮醇类化合物中，山奈酚具有多种生物活性，但植物来源的山奈酚价格昂贵，不能用于商业产品。最近，我们证实，绿色茶籽（GTS）含有合理数量的山奈酚糖苷。在进行结构分析后，鉴定了两种山奈酚糖苷，分别为山奈酚-3-O-[2-O-β-D-吡喃半乳糖基-6-O-α-L-吡喃鼠李糖基]-β-D-吡喃葡萄糖苷（化合物1）和山奈酚-3-O-[2-O-β-D-吡喃木糖基-6-O-α-L-吡喃鼠李糖基]-β-D-吡喃葡萄糖苷（化合物2）。此外，一个商业上有用的方法，山奈酚的制备建议酶水解使用这两种黄酮。在对化合物1和2进行多次酶反应以使其完全生物转化为山奈酚后，我们发现最佳的酶组合是与β-半乳糖苷酶和橙皮苷酶反应。最终得到纯度大于95%的山奈酚纯品。并比较了这两种GTS黄酮及其苷元山奈酚的抗氧化作用。山奈酚是一个更有效的1，1-二苯基-2-苦肼基自由基清除剂和一个更好的黄嘌呤/黄嘌呤氧化酶抑制剂比两个糖苷。
Among the flavonols in green tea, kaempferol has many biological activities but kaempferol of plant origin is too expensive to be used in commercial products. Recently, we confirmed that green tea seed (GTS) contained a reasonable amount of kaempferol glycoside. After conducting structure analysis, two kaempferol glycosides were identified, kaempferol-3-O-[2-O-beta-D-galactopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside (compound 1) and kaempferol-3-O-[2-O-beta-D-xylopyranosyl-6-O-alpha-L-rhamnopyranosyl]-beta-D-glucopyranoside (compound 2), respectively. Also, a commercially useful method for kaempferol preparation was suggested by enzymatic hydrolysis using these two flavonoids. After several enzyme reactions were performed for the complete bioconversion of compounds 1 and 2 to kaempferol, we found that the optimum enzyme combination was reaction with beta-galactosidase and hesperidinase. Finally, we produced pure kaempferol with over 95% purity. We also compared the antioxidant effect of these two GTS flavonoids and its aglycone, kaempferol. Kaempferol is a more efficient scavenger of 1,1-diphenyl-2-picrylhydrazyl radicals and a better inhibitor of xanthine/xanthine oxidase than the two glycosides.