A simple, sensible and reliable HPLC-DAD fingerprint analysis method for the raw materials of Oxytropisfalcata and Oxytropis chiliophylla, both of which were used as "Er-Da-Xia" in Tibetan medicines, was developed and then subsequently applied to analyze samples collected from different locations or times. 19 common fingerprint peaks for O. falcata, 24 for O. chiliophylla, and 11 for the two herbs were designated respectively, including 7 identified characteristic peaks existing in both herbs and 1 uniquely presenting in O. chiliophylla. Although there were some slight differences in the chemicals of O. falcata and O. chiliophylla, the main components of both herbs were consistent generally. The results provided scientific basis, at least from the chemical point of view, for the reasonablity of two herbs being used as the same drug in Tibetan medicines and for the necessary of further investigation on their detailed chemical and pharmacological differences.
Twenty-seven flavonoids, including 10 isoflavones, 9 flavanones, 3 dihydrochalcones, 3 flavonols and 2 flavans, were isolated from the whole plant of Tibetan medicine Oxytropis falcate Bunge. Structure elucidation was conducted by extensive spectroscopic analysis, including MS, NMR and CD spectra. Twelve compounds were obtained from this plant for the first time, among which 10 compounds were obtained from the genus of Oxytropis for the first time.