Rapid screening of glutathione-trapped reactive metabolites by linear ion trap mass spectrometry with isotope pattern-dependent scanning and postacquisition data mining.
The present study describes a novel integrated approach for rapid analysis of reactive metabolites with a linear ion trap mass spectrometer (LTQ). In this approach, an isotope pattern-dependent scanning method was applied to the data acquisition of glutathione (GSH)-trapped reactive metabolites. Recorded full-scan MS and MS/MS data sets were further processed with neutral loss filtering, product ion filtering, and extracted ion chromatographic analysis to search for protonated molecules and MS/MS spectra of GSH adducts. To evaluate the effectiveness and reliability of the approach, GSH adducts of carbamazepine, diclofenac, 4-ethylphenol, acetaminophen, p-cresol, and omeprazole were analyzed, which were formed in human liver microsome incubations fortified with a mixture of nonlabeled GSH and stable isotope-labeled GSH at a 1:0.8 ratio. Results demonstrate that the combination of the isotope pattern-dependent scanning with the postacquisition data mining was very effective in detecting low levels of GSH adducts, regardless of their fragmentation patterns. As compared to a neutral loss scanning method performed with a triple quadrupole mass spectrometer, the LTQ-based approach had several major advantages, including the superior selectivity and sensitivity in detecting different classes of GSH adducts and the higher throughput capability of the detection and MS/MS spectral acquisition of GSH adducts in a single LC/MS run. Overall, this analytical approach provides a simple and efficient means for screening for reactive metabolites using a linear ion trap LC/MS platform.
Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research and Development, Princeton, New Jersey 08543, USA.
Li
L
Ma
Bo
B
Wen
Qian
Q
Ruan
Mingshe
M
Zhu
D000082:Acetaminophen / Q000737:chemistry / Q000378:metabolism; D002220:Carbamazepine / Q000737:chemistry / Q000378:metabolism; D003408:Cresols / Q000737:chemistry / Q000378:metabolism; D004008:Diclofenac / Q000737:chemistry / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D005978:Glutathione / Q000032:analysis / Q000378:metabolism*; D009853:Omeprazole / Q000737:chemistry / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000737:chemistry / Q000378:metabolism*; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D011237:Predictive Value of Tests; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D003408:Cresols; D004364:Pharmaceutical Preparations; D010636:Phenols; D004008:Diclofenac; C032538:4-cresol; D002220:Carbamazepine; D000082:Acetaminophen; C042291:4-ethylphenol; D005978:Glutathione; D009853:Omeprazole