Preparative isolation and purification of hydroxyanthraquinones and cinnamic acid from the Chinese medicinal herb Rheum officinale Baill. by high-speed counter-current chromatography

A high-speed counter-current chromatography (HSCCC) method for preparative separation and purification of five hydroxyanthraquinones and cinnamic acid from the Chinese medicinal herb Rheum officinale Baill. was developed by using pH-gradient elution. The purities of rhein, emodin, aloe-emodin, chrysophanol, physcion and cinnamic acid were all over 98%, as determined by high performance liquid chromatography (HPLC). The structures of them were identified by 1H NMR.