白叶单枞黑茶降血糖活性成分的高速逆流色谱分离

Separation of bioactive compounds from dark tea prepared from Camellia sinensis var. baiye dancong using HSCCC target-guided by α-glycosidase inhibitory activity

摘要: 采用白叶单枞黑茶的60%乙醇提取物,在α-葡萄糖苷酶抑制活性的导向下,经D101大孔吸附树脂柱层析获得活性流分,进一步采用高速逆流色谱法（HSCCC）进行分离纯化研究。结果显示,黑茶60%乙醇提取物具有较显著的α-葡萄糖苷酶抑制活性,经D101柱层析所得的流分D-6、D-7及D-8在25μg/mL浓度下具有较黑茶60%乙醇提取物强的酶抑制活性,酶活性抑制率分别为69.31%、77.53%及75.23%。对活性流分D-7采用溶剂系统:乙酸乙酯-正丁醇-甲醇-水-乙酸（4∶1∶1∶4∶0.1,v/v）进行了HSCCC分离,得到化合物1、2,纯度均大于95%,经结构鉴定确定二者分别为牡荆苷、异牡荆苷。

Abstract: α-glycosidase inhibitors in dark tea were studied systematically by the method of a combination of extraction with 60% ethanol, fractionation on D101 column, and further purification by HSCCC ordinally. The result showed that fractions D-6, D-7 and D-8 obtained by D101 column chromatography indicated higher inhibitory activity than 60% ethanol extract of dark tea in the concentration 25μg/mL, inhibition were 69.31%、77.53% and 75.23%, respectively. Fraction D-7 was selected to further separation by HSCCC with solvent system ethyl acetate-n-buthanol-methanol-water-acetic acid (4∶1∶1∶4∶0.1, v/v) . Compound 1 (vitexin) and compound 2 (isovitexin) were obtained by one step HSCCC separation with purities higher than 95%, respectively.