[In vivo metabolism of three coumarins from Chimonanthi Radix based on UHPLC-QTOF-MS/MS]

Scopolin (SC-1), scopoletin (SC-2) and isofraxidin (IS-1) are the main active constituents in Chimonanthi Radix. However, the in vivo metabolism of SC-1, SC-2 and IS-1 have not been comprehensively clarified. In this study, the in vivo metabolic profiles of these three coumarins in the rat plasma, urine and feces were analyzed. Ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS/MS) method was applied to characterize the prototypes and metabolites of SC-1, SC-2 and IS-1 in rat feces, urine, and plasma after intravenous administration. A total of 11 metabolites of the three parent compounds were tentatively identified. The main metabolic pathways were analyzed by identification of metabolites, and it was found that these three coumarins underwent multiple in vivo metabolic reactions including glucuronidation, sulfonation, isomerism and reduction. In this study, the analysis of metabolites of three coumarins basically demonstrated their in vivo metabolic process, providing basis for the further pharmacokinetics and pharmacological evaluations of SC-1, SC-2 and IS-1.