HPLC analysis of a bioactive chalcone and triterpene in the buds of Cleistocalyx operculatus

Cleistocalyx operculatus is a well-known medicinal plant, the buds of which are commonly used as an ingredient of tonic drinks in southern China. To evaluate the quality of C . operculatus material, a simple, rapid and accurate HPLC method was developed for the quantitative/ qualitative assessment of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone and ursolic acid, the principal bioactive compounds in the buds of C . operculatus . The HPLC system was equipped with a C 18 reversed phase column, and methanol and aqueous H 3 PO 4 were used as the mobile phase. Peaks were detected at 220nm. The recovery of the compounds was 97.5% and 99.3%, respectively, for compounds 2’,4’-dihydroxy-6'-methoxy- 3',5'-dimethylchalcone and ursolic acid, and the two compounds showed good linearity (r 2 ≥ 0.9997) in a relatively wide concentration range. The concentration of these two phytochemicals in the buds of C . operculatus , growing at three different locations in China, was determined to establish the effectiveness of the method as well as the variability of the plant material.