决明子中大黄素的提取、分离和纯化方法的研究

目的寻求获得高纯度大黄素的可行性。方法先用稀硫酸溶液将蒽醌苷水解成苷元，再用热氯仿将苷元提取出来，然后用PH8．0缓冲液将大黄酸从氯仿液中除去，再用0．2％NaOH反复萃取将大黄素从氯仿液中提取出来，用层析柱法将大黄素分离纯化，经用丙酮反复多次重结晶可得纯度较高的大黄素。结果本方法提纯得到的大黄素的纯度达到98．1％以上。结论该方法操作简单、实用性强、成本低、可以推广应用。

Studies on the method of the extraction, isolation and identification of rhein in Cassia Obtusifolis L

Objective To seek the method of the feasibility that obtains highly pure Rhein. Methods Anthraquinone glycoside is hydroiysised to be its glycone in dilute sulfuric acid solution. The dissociated anthraquinone glyeone is extracted from medical material by hot chloroform. Emodie acid is removed by buffer solution （Ph8.0）. Rhein is extracted from hot chloroform Physcion solution by several extractions with 0. 2% NaOH, and Rhein is separated by column chromatography. The high purity chrysophanol is obtained by several crystallizations with acetone. And its content is determined by HPLC. Results The purity of Rhein obtained in this method can reach over 98.1%. Conclusion This method is characterized by simple operation, strong utility and low cost, which is also applied to mass production.