High-Resolution Liquid Chromatography-Mass Spectrometry-Based Metabolomic Discrimination Of Citrus-Type Crude Drugs And Comparison With Nuclear Magnetic Resonance Spectroscopy-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 (H-1) and C-13 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 H-1 and C-13 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 secondary metabolites with high sensitivity, some of which occurred in quantities that were undetectable using NMR spectroscopy.