Determination of oleanolic acid and ursolic acid contents in Ziziphora clinopodioides Lam. by HPLC method

A simple, precise, rapid and accurate, binary-phase high performance liquid chromatographic method has been developed for the determination of oleanolic acid and ursolic acid contents in the Ziziphora clinopodioides Lam. with short run time. Chromatographic separation is achieved by using HPLC system consisting of a Shimadzu LC-6AD and Kromasil C ₁₈ column (150 Χ 4.6 mm, 10 ΅m, with pre-column), the mobile phase consists of methanol and 0.03 M phosphate buffer (pH = 3, 90:10). Detection wavelength is 214 nm. The speed of flow is 0.5 ml/min. The specimen handing quantity is 10 μl. The oleanolic acid's linearity range is 0.4~1.2 mg/ml (r = 0.9996). The ursolic acid's linearity range is 0.6~1.8 mg/ml (r = 0.9996), and the linear relationship is accurate. The average recovery (n = 6) of oleanolic acid is 99.5% (RSD = 1.19%) and ursolic acid is 102.3%(RSD = 1.25%). The content of oleanolic acid and ursolic acid in Ziziphora clinopodioides are 0.76 mg/g and 1.176 mg/g, respectively. The developed HPLC method can therefore be applied to both in vitro studies of oleanolic acid and ursolic acid formulations as well as drug estimation in biological samples.