Polyphenolic constituents from Chestnut needles and their biological activities

我们对板栗针叶中的多酚成分进行了分析，分离出了14种酚类化合物，包括水解性单宁和鞣花酸衍生物。此外，还从天然资源中分离得到了从可水解单宁中提取的鞣花酸3-C-葡萄糖苷。通过ORAC试验和类超氧化物歧化酶活性检测，所有菌株均显示出较强的抗氧化活性。水解性单宁也有抑制酪氨酸酶的作用，而已知具有美白作用的鞣花酸则没有活性。此外，鞣花酸3-C-葡萄糖苷对黑色素瘤B16细胞黑素合成的抑制作用强于熊果苷阳性对照，细胞毒性低。

We examined the polyphenolic constituents in chestnut needles and isolated fourteen phenolics including hydrolyzable tannins and ellagic acid derivative. Also, ellagic acid 3-C-glucoside which was derived from hydrolyzable tannins and was not yet isolated from natural resources was obtained. All the isolates showed potent antioxidative activities evaluated by ORAC test and SOD-like activity. Hydrolyzable tannins also exert tyrosinase inhibitory effect meanwhile ellagic acids which are known to have skin-whitening ability showed no activity. Additionally, ellagic acid 3-C-glucoside showed potent inhibitory effect against melanogenesis of melanoma B16 cells than the positive control of arbutin with low cytotoxicity.