Objective:The metabolites of brazilin were detected and identified in vivo. Method:The metabolic profiles of brazilin in plasma

urine

bile and feces samples after oral administration (30 mg·kg-1) were analyzed by UPLC-Q-TOF-MS/MS.The mobile phase was consisted of water(containing of 0.1% formic acid)-acetonitrile and eluted in gradient mode.The mass was detected in negative ion mode and information dependent acquisition(IDA) model was used.The data were analyzed by PeakView 1.2 software.Total ion chromatogram of sample was extracted and compared with the blank biological sample

possible metabolites were screened and identified by comparison and analysis of retention time

precise molecular mass

elemental composition and secondary mass spectrometry. Result:Twenty-three metabolites of brazilin were detected by comparing with the blank sample.The pathways to these metabolites were methylation

deoxygenation

hydrogenation

carboxylation

hydration

sulfation and glucuronide conjugation

in which sulfation and glucuronide conjugation were the main transitions. Conclusion:This study provides the metabolism of brazilin in rats for the first time

which can be useful for its pharmacology and pharmacodynamics.