Van Nguyen1, Michael J. Espiritu1, Fawzy Elbarbry1
1Department of Pharmacy, Pacific University School of Pharmacy, Hillsboro, OR, USA
Tóm tắt
AbstractA sensitive and specific liquid chromatography tandem mass spectrometric (LC–MS/MS) method that enables the simultaneous quantification of probe substrates and metabolites of cytochrome P450 (CYP) enzymes was developed and validated. These substrates (metabolites)—coumarin (7‐hydroxycoumarin), tolbutamide (4‐hydroxytolbutamide), S‐mephenytoin (4‐hydroxymephenytoin), dextromethorphan (dextrorphan), and testosterone (6β‐hydroxytestosterone)—were utilized as markers for the activities of the major human CYP enzymes CYP2A6, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, respectively. Analytes were separated on Kinetex C18 column (2.1 × 50 mm, 5 μm) using a binary gradient mobile phase of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Metabolites were detected and quantified by MS using multiple reaction monitoring at m/z 163 → 107.2 for 7‐hydroxycoumarin, m/z 235 → 150.1 for 4‐hydroxymephenytoin, m/z 287 → 171 for 4‐hydroxytolbutamide, m/z 258 → 157.1 for dextrorphan, m/z 305 → 269 for 6β‐hydroxytestosterone, and m/z 237 → 194 for the internal standard. The assay exhibited good linearity over a range of 10–500 ng/mL with acceptable accuracy and precision criteria.As a proof of concept, the developed cocktail assay was successfully used to examine the potential impact of catechin on the activity of the major rat liver CYP enzymes.
