Multi-level characterization and comparison of polysaccharides and small-molecule metabolites enabling the differentiation of three Codonopsis species

Discrimination among the Dang-Shen varieties (including Codonopsis pilosula , Codonopsis pilosula var. modesta , and Codonopsis tangshen ), consumed daily as the healthy diet, is rather challenging. This work, targeting differentiation among three Codonopsis species, was designed to comprehensively characterize and compare the polysaccharides by three-level fingerprinting and small-molecule metabolites by liquid chromatography-mass spectrometry-based untargeted metabolomics. Polysaccharides from the roots of three Codonopsis species showed indistinctive differentiation in the distribution of molecular weight, and similar oligosaccharide profiles resolving 2–25 polymerization degrees of oligosaccharides. Seven common monosaccharides were detected for three species, in which Glc, GalA, and Gal/Ara were the potential sugar markers. In addition, the small-molecule metabolites in 50 batches of three Codonopsis species exhibited significant differentiations, and separately three, nine, and 11 potential markers were discovered and utilized as key identification points, respectively. Conclusively, holistic comparison from the polysaccharides and small-molecule metabolites together offers new evidence for better quality control of Codonopsis .