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.
A series of E and Z-isomers of 3-（4＇-substituted benzylidene）-indolin-2-one derivatives were synthesized and separated. Based on their 1H NMR characterization, an unusual counterintuitive deshielding phenomenon for the protons presenting in the shielding zone of phenyl ring was observed and analyzed for the first time.
The root of Hedysarum multijugum（RHM） is recorded as a folk herbal medicine in China and is sometimes used as a substitute for Hedysari Radix, which is a famous traditional Chinese medicine derived from the roots of Hedysarum polybotrys. In the present study, a sensible, reliable, and reproducible HPLC-DAD fingerprint analysis method for RHM was developed and then subsequently applied to analyze RHM samples from different origins. The chemical constituents of the RHM samples were generally consistent, although it was slightly affected by the local environment of the plant. In addition, the chemical constituency of RHM was shown to be significantly different from that of Hedysari Radix, suggesting that RHM is not suitable as a substitute for Hedysari Radix, at least from the chemical point of view.
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.
