Untargeted Metabolomic Analysis and Chemometrics to Identify Potential Marker Compounds for the Chemical Differentiation of Panax ginseng, P. quinquefolius, P. notoginseng, P. japonicus, and P. japonicus var. major.

The Panax L. genus is well-known for many positive physiological effects on humans, with major species including P. ginseng, P. quinquefolius, P. notoginseng, P. japonicus, and P. japonicus var. major, the first three of which are globally popular. The combination of UPLC-QTOF-MS and chemometrics were developed to profile "identification markers" enabling their differentiation. The establishment of reliable biomarkers that embody the intrinsic metabolites differentiating species within the same genus is a key in the modernization of traditional Chinese medicine. In this work, the metabolomic differences among these five species were shown, which is critical to ensure their appropriate use. Consequently, 49 compounds were characterized, including 38 identified robust biomarkers, which were mainly composed of saponins and contained small amounts of amino acids and fatty acids. VIP (projection variable importance) was used to identify these five kinds of ginseng. In conclusion, by illustrating the similarities and differences between the five species of ginseng with the use of an integrated strategy of combining UPLC-QTOF-MS and multivariate analysis, we provided a more efficient and more intelligent manner for explaining how the species differ and how their secondary metabolites affect this difference. The most important biomarkers that distinguished the five species included Notoginsenoside-R(1), Majonoside R(1), Vinaginsenoside R(14), Ginsenoside-Rf, and Ginsenoside-Rd.