Isolation of oleanolic acid from Clematis armandii for differentiation it from adulterants by HPTLC/HPLC

Clematis armandii has been used in many Chinese traditional patent medicines all over the world as a form of Caulis Clematidis Armandii. However, it has often been adulterated by Aristolochia manshuriensis, and Iodes vitiginea. A. manshuriensis must not be part of any herbal medicines because it contains aristolochic acid I, a nephrotoxin and potential carcinogen. The current pharmacopoeial methods have had limitation for differentiation of C. armandii from its adulterants. Thus, a specific, comprehensive, sensitive, and reproducible HPTLC/HPLC for quality control of C. armandii was proposed. Oleanolic acid from C. armandii has been isolated by vacuum liquid chromatography and column chromatography. The purified compound has been identified using Ultra Violet spectrophotometry (UV–Vis), Fourier Transform Infrared (FTIR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Therefore, oleanolic acid should be detected for positive identification of Caulis Clematis Armandii. Minimum content of oleanolic acid can be evaluated by the validated HPTLC procedure proposed as well.