Metabolites identification and reversible interconversion of chelerythrine and dihydrochelerythrine in vitro/in vivo in rats using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

•A rapid Q-TOF-MS method was developed for metabolites identification of CHE and DHCHE.•The biotransformation patterns of CHE in vitro/in vivo were elucidated.•The biotransformation patterns of DHCHE in vitro/in vivo were elucidated.•Reversible interconversion between CHE and DHCHE in vivo was confirmed.