Distinctive features of chemical composition of Bupleurum chinense applicable to original authentication

Abstract

The original determination of plant-derived subjects in traditional herbal medicines is often complicated by the lack of morphological features in visual or microscopic inspection. Improved methods are urgently needed. In this paper, the proton nuclear magnetic resonance (¹H NMR) and high performance liquid chromatography (HPLC) profiles of fractionated polar extracts from samples of Bupleurum chinense were recorded and analyzed by comparing them to each other and to those of the isolated compounds. The ¹H NMR spectra revealed distinct common features among collected samples of B. chinense, with the characteristic signals of their major constituents, saikosaponins, being exhibited explicitly and reproducibly. These features were further confirmed by HPLC and online HPLC/MS (mass spectrometry) analysis. Also, thirty-five compounds, including twenty-seven saikosaponins and eight others, were isolated from the extracts of the roots of B. chinense. On the basis of chemical investigation, the signals and peaks in the fingerprints were unambiguously assigned to their corresponding compounds. The general features of ¹H NMR spectra coupled with HPLC profiles established for authentic samples of B. chinense gave specific data for those particular compounds and can be used for original authentication.