Identification of in vitro and in vivo metabolites of isoimperatorin using liquid chromatography/mass spectrometry

► Isoimperatorin metabolites were identified with LC/QTRAP-MS and LC/TOF-MS. ► 19 Metabolites were characterised in rat urine, plasma, bile and faeces. ► Four metabolites were first prepared and one was a novel compound. ► 13 Products were identified from Cunninghamella blakesleana transformation. ► Oxidation in the side chain of isoimperatorin was the primary metabolic pathway.