Integration of multiplatform metabolomics and multivariate analysis for geographical origin discrimination of Panax ginseng

Abstract

As the health food industry grows, the market for ginseng also expands globally. Korean ginseng (Panax ginseng C. A. Meyer) is cultivated in East Asian countries such as Korea, China, and Japan. The metabolic profile of plants can vary depending on the cultivation environment. As such, in this study, we aimed to compare the differences in the metabolic profiles of P. ginseng cultivated in Korea, China, and Japan, and to construct a library of these metabolite data. Using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS), we profiled 62 types of secondary metabolites, ginsenosides, using optimized analysis conditions to separate peaks with a high-resolution for about 30 min. In addition, we selected ginsenosides showing differences between their origins were selected among the possible origins in the S-line plot of orthogonal partial least squares discriminant analysis (OPLS-DA), which we quantitatively analyzed using UPLC-tandem mass spectrometry (UPLC-MS/MS). The contents of ginsenosides Ra1, Ra2, Ra3, and Rk1 were high in Korean P. ginseng; the contents of ginsenosides Rb1, Rb2, and Rc were high in Japanese P. ginseng; and the contents of the ginsenoside Ro was high in Chinese P. ginseng. We also analyzed the primary metabolite contents using nuclear magnetic resonance (NMR) spectroscopy and gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). Japanese P. ginseng showed a high sucrose content and Korean P. ginseng showed high contents of most amino acids and organic acids. In the PLS-DA results of multivariate statistical analysis using the data obtained from each analysis instrument, we observed a clear clustering among the three origins. Although a genetically identical species, the metabolic profile substantially differs depending on the cultivation environment. Because ginsenoside, having many biological activities, showed origin-dependent origins, when P. ginseng is used for medicinal purposes, its content by origin should be considered. After disclosing the profiling results of these metabolites, we expect that they will be used in future ginseng research.

Keywords: GC-TOF/MS; Metabolomics; Multivariate statistical analysis; NMR spectroscopy; Panax ginseng C. A. Meyer; UPLC-QTOF/MS.