title: Rapid and quantitative determination of metabolites from multiple cytochrome P450 probe substrates by gradient liquid chromatography-electrospray ionization-ion trap mass spectrometry.
abstract: A rapid quantitative assay method, developed by combining fast gradient liquid chromatography and electrospray ionization-ion trap mass spectrometry, is described for the simultaneous determination of CYP450 probe substrate metabolites (4-aminophenol for CYP2E1, acetaminophen for CYP1A2, dextrorphan for CYP2D6, 4'-hydroxymephenytoin for CYP2C19, 4-hydroxytolbutamide for CYP2C9 and 6beta-hydroxytestosterone for CYP3A4) in microsomal incubations. Using this method Michaelis-Menten kinetic parameters K(m) and V(max) for the probe substrates in human liver microsomes were obtained. This LC-MS-MS method, developed with the use of LC-ESI-ion trap MS instrumentation, can efficiently be used to improve the throughput and cost-effectiveness in the preclinical drug metabolism studies.
authors.affiliation: Bioanalytical Systems, Inc, 2701 Kent Avenue, West Lafayette, IN 47906, USA.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Zhang
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Chandrani
authors.initials: C
authors.lastname: Gunaratna
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology; D011786:Quality Control; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013379:Substrate Specificity
chemical_list: D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System