Rapid characterization of chemical constituents and rat metabolites of Fufang Gancao Tablets by UHPLC-LTQ-Orbitrap mass spectrometer

Abstract

Ultra-high-performance liquid chromatography coupled with tandem high-resolution mass spectrometry (UHPLC-HR-MSn ) method was used to analyze the constituents of Fufang Gancao Tablets and its main metabolites in rat plasma. Rat plasma was collected both before and after oral administration of Fufang Gancao Tablets. After solid phase extraction, ACQUITY UHPLC BEH C₁₈ (2.1 mm×100 mm, 1.7 μm) was used with 0.1% formic acid-acetonitrile solution as the mobile phase for gradient elution. The chemical components in Fufang Gancao Tablets and their prototypes and metabolites in plasma samples were analyzed by LTQ-Orbitrap equipped with an ESI ion source in a positive ion mode. Based on the accurate mass measurements, the retention time and mass fragmentation patterns, a total of 55 compounds were tentatively identified from Fufang Gancao Tablets, including 42 flavonoids, 9 triterpenes and 4 alkaloids. Furthermore, metabolites in rat plasma after oral administration of Fufang Gancao Tablets were also analyzed. A total of 26 compounds were identified, including 20 prototypes and 6 metabolites mainly through metabolic pathways of hydroxylation, glucuronide conjugation, and sulfate conjugation, etc. Our results showed that the ultra-high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high resolution mass spectrometry (UHPLC-LTQ-Orbitrap) could comprehensively elucidate the chemical constituents of Fufang Gancao Tablets and their migrating components in rat plasma, providing scientific basis for further studying the metabolism process and pharmacodynamic substance of Fufang Gancao Tablets.