Metabolic profiling of Gegenqinlian decoction in rat plasma, urine, bile and feces after oral administration by ultra high performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry.

Gegenqinlian decoction (GQLD) as a traditional Chinese medical (TCM) prescription is made from four Chinese herbs and has been used for centuries to treat pyrexia and diarrhea. In this work, an ultra-high performance liquid chromatography coupled with Fourier transform ion cyclotron resonance mass spectrometry (UHPLC-FT-ICR-MS) method was established to profile the metabolic fate of GQLD in rat plasma, urine, bile and feces. The analysis was performed on a Waters Acquity UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 μm) at 35 °C within 25 min. A total of 174 compounds mainly including flavonoids, alkaloids and triterpenoids in rat plasma, urine, bile and feces after oral administration of GQLD were identified or tentatively characterized by comparison with retention times, accurate mass within 5 ppm error and their characteristic MS fragmentation ions. Among compounds in rats, 107 compounds are prototypes and 67 compounds are metabolites. Results demonstrated that metabolic pathways of GQLD in rats included methylation, demethylation, hydrogenation, hydrolysis, hydroxylation, methoxylation, sulfate conjugation and glucuronide conjugation. A clear understanding of the absorption and metabolism of GQLD is very important in its rational clinical use and pharmacological research. These findings enhance our understanding of the metabolism and effective forms of GQLD.