The Study Of Separating Active Compounds From Natural Plants By Countercurrent Chromatography

Countercurrent chromatography (CCC) is a continuous liquid-liquid partition chromatography without solid support matrix. Therefore, it has several advantages compared with traditional solid-liquid chromatography for the separation of the natural products. In this dissertation, two natural products were studied as the samples. Two CCC methods were developed for their separations. The details are in the following:1. A new separation method was developed to separate the bioactive components in the crude extract of Gynura bicolor DC (which Chinese name is Zibeicai). With subsequent two CCC separation with different solvent systems, a compound with relative high purity was separated. The solvent system composed of n-hexane- ethyl acetate-methanol-water with volume ratio 1:6:1:6 and 1:3:1:3 were used in the two steps independently. The primary structure of the separated compound was identified by MS/MS and HRMS.2. A method was established for the separation of the polar alkaloids from the crude sample by CCC coupled with the analysis of HPLC-MSn. Two alkaloids were isolated from the polar fraction of S. yunnanensis by CCC. Besides, the polar fraction of S. yunnanensis was analyzed by HPLC-MS". Three other alkaloid compounds were given promising structures through the analysis of the fragmentation.