Evidence for Glucuronide and Glutathione Conjugation of Glyceollins in Rats by On-Line Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry

摘要

Identified Phase I and Phase II metabolites from rat plasma, urine, and feces samples originating from rats dosed with glyceollins. Phase I metabolism includes epoxidation, hydroxylation, diol addition to glyceollins, while Phase II metabolism includes sulfation, glucuronidation, plus observation of cysteinylglycine, and cysteine conjugates of glyceollins. M/z 474 and 531 were identified as cysteine and cysteinylglyceine conjugates of glyceollins with an addition of an oxygen, respectively. The assignments were further confirmed by examining these conjugates in positive ion mode. Glutathione addition is proposed to occur at an epoxide site formed during Phase I metabolism of glyceollins. Glucuronide conjugates of glyceollins were identified from rat plasma and urine only.