制备型逆流色谱分离绿茶提取物中儿茶素单体

为了进一步研究儿茶素的作用机理，对自制的制备型逆流色谱分离纯化绿茶提取物中多种儿茶素单体的技术进行了研究，采用两组溶剂系统，一组是石油醚-乙酸乙酯-水(0．2：1：2)；另一组是正丁醇-乙酸乙酯-水(0．2；1：2)系统，每次实验进样量为4g绿茶提取物，用前一组溶剂系统，表儿茶素(EC)、表没食子儿茶素没食子酸酯(EGCG)、没食子儿茶素没食子酸酯(GCG)和表儿茶素没食子酸酯(ECG)得到了很好的分离，每一种单体的纯度达到了98％，其中ECGC达到99％；用后一组溶剂系统，表没食子儿茶素(EGC)、儿茶素(士C)得到了分离，纯度达到92％。

Preparative Isolation and Purification of Catechins from Green Tea Extract by Preparative Counter-Current Chromatography

A preparativecounter-current chromatography instrument is made and catechins from greentea extract are successfully isolated and purified with it in this experiment. Two pairs of two-phasesolvent systems are used. One of solvent system is petroleum ether- ethyl acetate- water at volume rarios of 0.2: 1: 2 and the other is n-butanol-ethyl acetate--water at volume ratios of 0.2: 1: 2.4 g crude extract is injected each run. The results show that four major components including (-)-epicatechin (EC), (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG)and ( - )-epicatechin gallate(ECG) are isolated by the first solvent systems, each at over 98% purity. Othermajor components, such as (-)-epigallocatechin (EGC), ( + )-catechin (± C) are isolated by the lastsolvent systems, each at over 92% purity.