人参皂苷Rg_3异构体的简易分离制备

A simple technology for separation of ginsenoside Rg3 enantiomers

目的：分离制备20-(S)-Rg3与20-(R)-Rg3两种手性人参皂苷。方法：根据两者在不同浓度的乙醇溶液中溶解度的差异，通过改变溶液的乙醇浓度，借助沉淀和结晶手段，实现两者的分离。结果：20-(S)与20-(R)-Rg3含量分别为60％和40％的混合样品，经本方法一次分离后，20-(S)-Rs的收率≥60％，20-(R)-Rg3≥65％，两者纯度均≥95％。结论：本方法简单、方便、快速、处理量大、经济，不使用手性试剂或手性柱，是一种较好的分离纯化手段，极易开发成大规模的制备方法。

Objective: To establish a method to prepare ginsenoside Rg3 (G-Rg3) enantiomers on a large scale. Methods: Based on different solubilities in ethanol, G-20-(S)-Rg3 and G-20-(R)-Rg3 were separated by precipitation and crystallization. Results:The G-Rg3 enantiotopic mixture contained 60% of ginsenosides G-20-(S)-Rg3 and 40% of 20-(R)-Rg3.By the preparation, the recovery rate of G-20-(S)-Rg3 was≥60% , and 20-( R )-Rg3≥65% , and the purity of both Rg3 enantiomers was achieved at ≥95% . Conclusion:This method offers greater advantages in term of not only efficiency, convenience and low cost, but also no chiral agents or chiral chromatographs needed, thereby resulting in a potential preparation technology on a large scale for ginsenoside Rg3 enantiomers.