To deeply understand the chemical components and functional differences of the rhizomes from different Coptis species, this study employed widely targeted metabolomics for the metabolic profiling of C. chinensis, C. deltoidea, and C. teeta. A total of 658 metabolites including alkaloids, lipids, flavonoids, and phenolic acids were identified. The result of principal component analysis(PCA) revealed significant differences of the metabolites among different Coptis species. C. chinensis had a richer variety of total alkaloids than C. deltoidea and C. teeta. According to the results of orthogonal partial least squares-discriminant analysis(OPLS-DA) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis, the differential metabolites of the three species were significantly enriched in the secondary metabolic pathways dominated by the biosynthesis of isoquinolines. The cluster analysis of shared differential metabolites showed that alkaloids accounted for the largest proportion. The content of total alkaloids in C. chinensis was significantly higher than that in C. teeta and C. deltoidea. S-Plot was employed to predict the metabolic markers and the key differential secondary metabolites related to the pharmacological effects of Coptidis Rhizoma were analyzed. The results showcased that the relative content of berberine and palmatine in C. chinensis was significantly higher than that in C. teeta and C. deltoidea, and thus the two components could serve as biomarkers for metabolic differences among the three Coptis species. This study provided basic data for the overall evaluation and breeding of Coptis resources, laying a foundation for further quality control and precise medication of Coptidis Rhizoma.
Keywords: Coptidis Rhizoma; chemometrics; differential metabolites; ultra high performance liquid chromatography tandem mass spectro-metry; widely targeted metabolomics.