Identification of major compounds in rat bile after oral administration of total triterpenoids of Ganoderma lucidum by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry

Triterpenoids are the main bioactive components of Ganoderma lucidum, a famous traditional Chinese medicine. After oral administration of total triterpenoids of G. lucidum (TTGL), the rat bile was analyzed by high-performance liquid chromatography coupled with diode array detection and electrospray ion trap tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) and liquid chromatography coupled with electrospray ionization hybrid ion trap and time-of-flight mass spectrometry (LC-ESI-IT-TOF/MS). From rat bile and TTGL samples, a total of 31 triterpenoids, including seven new compounds, were identified or tentatively characterized based on their fragmentation behaviors. Among them, 22 triterpenoids were identified from TTGL and 29 triterpenoids were detected from rat bile after oral administration of TTGL. The results indicated that the majority of triterpenoids detected in TTGL extract could be excreted through rat bile. It is the first report on excretion of total triterpenoids of G. lucidum in rat bile.