pH-modulated stepwise elution CCC and its application to the preparative separation of hydroxyanthraquinone compounds from traditional Chinese medicinal herbs

Analytical and preparative high-speed countercurrent chromatography was successfully used for the separation of hydroxyanthraquinones from traditional Chinese medicine such as Rheum officinale Baill (Dahuang) and Polygonum cuspidatum Sieb. Et Zucc (Huzhang) using pH-modulated stepwise elution. Four major components including chrysophanol, emodin, physcion, and aloe-emodin were isolated each at over 98% purity.