Identification of the major metabolites of tectorigenin in rat bile by liquid chromatography combined with time-of-flight and ion trap tandem mass spectrometry.

A novel methodology for the identification of tetorigenin and its metabolites in rat bile has been created using liquid chromatography (LC) combined with time-of-flight (TOF) and ion trap multiple mass spectrometry (IT-MSn). As a means to discriminate amongst unknown organic compounds in complex biological matrices, the proposed methodology relies upon the combination of LC/TOF-MS to provide accurate mass measurements in generating a molecular formula while benefiting from the complementary structural information provided by the LC/IT-MSn. In this study, the combined approach has been applied to the metabolic fingerprinting chromatograms of rat bile samples before and after tectorigenin administration. All possible metabolites are investigated based on accurate mass data and isotope function using LC/TOF-MS and structural confirmation using LC/IT-MSn. Seven phase II metabolities of tectorigenin in rat bile have been successfully elucidated using this novel LC approach and are being reported for the first time.