Comparative chemical analysis of Radix Astragali and Radix Hedysari by HPLC.

Radix Astragali and Radix Hedysari, two famous traditional Chinese medicines (TCM), were considered to possess the same efficacy in TCM traditionally. However, modern pharmacological and phytochemical investigations showed that they were different in efficacy and chemical constituents to some degree. In this study, the principal constituents of the two drugs, isoflavonoids and saponins, were comparatively analysed using HPLC-UV and HPLC-ELSD methods. The results showed that there were some common compounds, especially flavonoids, in both drugs, while the differences in the types and contents of their chemical constituents, especially in saponins, were also obvious. The similarities and differences of the chemicals may be responsible, at least partially, for the similarities and differences in their efficacies or bioactivities.