Metabolic Profile of Dendrobine in Rats Determined by Ultra-high-performance Liquid Chromatography/Quadrupole Time-of-flight Mass Spectrometry

Aims: Dendrobine is a major alkaloid present mainly in dendrobium nobile Lindl. It has been reported to have analgesic, antipyretic, lower heart rate and blood pressure and other pharmacologic activities. Despite its critical pharmacological function, its metabolite profiling is still unclear. Methods: In this study, the in vivo metabolite profiling of dendrobine in rats was investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). The metabolites were predicted using MetabolitePilotTM software with a mass defect filter (MDF) technique. These predicted metabolites were further analyzed by MS² spectra and compared with the detailed fragmentation pathway of the dendrobine standard and literature data. Results: Total of 59 metabolites were identified for the first time in rat plasma and urine after oral administration of dendrobine. Demethylated, dehydrogenated, hydroxylated, ketonizated and glucuronide were the major metabolic pathways. Conclusion: This research provides scientific and reliable support for full understanding of the metabolic fate of dendrobine in vivo.