Chemical comparison of the raw and processed Farfarae Flos by liquid chromatography-mass spectrometry based metabolomic approach.

Farfarae Flos (FF) has been used in China for a long time as an anti-tussive and expectorant herbal drugs, and it was usually honey-fried FF (HFF). To clarify the mechanism of honey processing, it is important to know the chemical difference between FF and HFF firstly. In this study, UHPLC-Orbitrap-MS was used to characterize the chemical compounds in FF, honey and HFF. Then the metabolomic approach based on UHPLC-Orbitrap-MS revealed 68 differential compounds between the FF and HFF, and chemical reactions occurring during processing were also proposed to elucidate the honey processing mechanisms of FF. In order to investigate the chemical difference between FF and HFF comprehensively and accurately, the components derived from the honey and the moisture content in FF and HFF were considered for the first time. In summary, this study investigated the chemical differences between FF and HFF in a holistic way, which laid the basis for the quality control of HFF and further explaining the honey processing mechanisms of FF. In addition, eight native compounds derived from the honey could be used as the index to authenticate the HFF prepared by the genuine honey.