Simultaneous quantification of three major bioactive triterpene acids in the leaves of Diospyros kaki by high-performance liquid chromatography method.

The leaf of Diospyros kaki, which is a traditional Chinese medicine, has been used for the treatment of various diseases. In order to improve the quality assurance of the leaves of D. kaki, derived extracts and phytomedicines, a simple, rapid and accurate high-performance liquid chromatography (HPLC) method was developed to simultaneously assess the three bioactive triterpene acids: barbinervic acid (BA) and its epimer, rotungenic acid (RA), along with 24-hydroxy ursolic acid (HA). This HPLC assay was performed on a reversed-phase C18 column with methanol and aqueous H3PO4 as the mobile phase and using a monitoring wavelength at 210 nm. This method was successfully applied to quantify these three bioactive triterpene acids in five different solvent extracts of the leaves of D. kaki and in the leaves from six different locations in China. The results demonstrated the total content and quantity of each of the main bioactive compounds were strongly dependent on the extraction solvents and locations, indicating that the quality control of the bioactive ingredients in the leaves of D. kaki, derived extracts and phytomedicines is critical to ensure its clinical benefits. The content of the total triterpenoids was also determined by the less selective colorimetric method, and the comparison with the HPLC method was given.