High-Resolution Liquid Chromatography–MassSpectrometry-Based Metabolomic Discrimination of Citrus -Type Crude Drugs and Comparison with Nuclear Magnetic ResonanceSpectroscopy-Based Metabolomics

Five Citrus-type crude drugs (40 samples) were classified using liquid chromatography–mass spectrometry (LC-MS)-based metabolomics. The following six flavonoid derivatives were identified as contributors from the loading plots of multivariate analysis: naringin (1), neohesperidin (2), neoeriocitrin (3), narirutin (9), hesperidin (10), and 3,5,6,7,8,3′,4′-heptamethoxyflavone (12). Three coumarin derivatives, namely, meranzin (6), meranzin hydrate (7), and meranzin glucoside (8), were also identified as contributors. Furthermore, compared with our previous studies on proton (1H) and 13C NMR spectroscopy-based metabolomics, the present study revealed that the Citrus-type crude drugs were distinguished with the same pattern; however, the contributors differed between the 1H and 13C NMR spectroscopy-based metabolomics. The high dynamic range of NMR spectroscopy provided broad coverage of the metabolomes including the primary and secondary metabolites. However, LC-MS appeared to be superior in detecting seconda...