Comparison of chemical constituents of Bupleurum marginatum var. stenophyllum and Bupleurum chinense DC. using UHPLC–Q‐TOF–MS based on a metabonomics approach

The overall chemical composition of Bupleurum marginatum var. stenophyllum and Bupleurum chinense DC. was compared in this study. Metabolites were identified using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Multivariate statistical analysis techniques such as principal component analysis were used to conduct metabonomics analysis and study the correlation between different components. Principal component analysis results showed a clear distinction among medicinal materials of different origins and divided them into different categories, consistent with the results of hierarchical cluster analysis. Both partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA) showed that the two materials could be distinguished clearly. Using PLS-DA and OPLS-DA combined with the S-plot and a variable importance in the projection (VIP) score >1, 24 differential metabolites were screened and identified; all of the metabolites were triterpenoid saponins. In addition, SPSS 25.0 and Metabo Analyst 4.0 were used to analyze significant differences in the relative contents of different compounds in the two materials. This study has successfully provided not only a new direction for research based on the chemical substances identified and the quality evaluation of Bupleuri Radix but also a better theoretical basis for the expansion of medicinal sources and their clinical application.