In vivo metabolite identification of bakuchiol in rats by UPLC/ESI–PDA–QTOF–MS

Psoralea corylifolia L. is a traditional Chinese medicine for the treatment of various skin diseases such as psoriasis, vitiligo and chronic graft-versus-host. Bakuchiol, isolated from the seeds of P. corylifolia L., is one of the most important active compounds. To study the metabolic fate of bakuchiol in rats, an ultra performance liquid chromatography/electrospray ionization-photo diode array-quadrupole time of flight-mass spectrometry (UPLC/ESI-PDA-QTOF-MS) combined with MetaboLynx XS software was used, peak area-time curves of major metabolites in plasma from bakuchiol were determined. A total of 11 metabolites were identified after a single oral administration of bakuchiol, including 6 in plasma, 10 in bile, 8 in urine and 2 in feces, the metabolic transformation pathways of bakuchiol in rats included oxidation, hydroxylation, methylation, O-glucuronide conjugation and O-sulfate conjugation. In conclusion, this study expands our knowledge about the metabolism of bakuchiol which will be conducive to reveal its in vivo pharmacological and toxicological material basis, in addition, UPLC/ESI-PDA-QTOF-MS coupled with MetaboLynx XS software can be adopted as a useful tool for quick detection and identification of metabolites from medicine in vivo.