Identification of Gambogic Acid Metabolites in Rat Bile by Liquid Chromatography-tandem Mass Spectrometry-ion Trap-time-of-flight

AimTo investigate the metabolism of gambogic acid in vivo in rat bile.MethodsLiquid chromatography-tandem mass spectrometry-ion trap-time-of-flight system and the authentic compounds were used to perform metabolism studies.ResultsGambogic acid was rapidly metabolized to three metabolites, M1, M2 and M3, in rat bile. M1 was tentatively presumed to be 3, 4-dihydro-gambogic acid. M2 and M3 were proved to be 10-hydroxy-gambogic acid and 9, 10-epoxy-gambogic acid.ConclusionGambogic acid was metabolized to three metabolites in rat bile. M1 is firstly reported, while the structures of M2 and M3 were confirmed by comparing the tandem mass spectra and the chromatographic retention time with those of the respective authentic compounds.