Determination of the geographical origin of Rehmannia glutinosa by NMR, UPLC-QTOF/MS and multivariate statistical analysis

Rehmannia glutinosa is a widely used medicinal herb in the domestic market. The type and composition of metabolites and the efficacy of medicinal herbs can vary depending on variances in cultivation environment, such as origin. Metabolomic approaches can be used to objectively determine the geographical origin. In this study, Korean and Chinese R. glutinosa were analyzed using a multi-platform based on nuclear magnetic resonance spectroscopy and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry. A multivariate statistical analysis of non-targeted analysis data and a comparison of quantitative analysis results of primary and secondary metabolites confirmed the differences between Korean and Chinese R. glutinosa. In the biomarker analysis, the metabolites resulting from the discrimination of geographical origin included various of organic acids such as malate, etc. It was found that organic acids can change based on environmental circumstances and that they play a significant role in growth, such as solubilizing nutrients.