Abstract
This study describes the application of the mass defect filter method for the detection of two unpredicted oxazole- ring opened metabolites of muraglitazar in the feces of humans following oral administration. Unlike other muraglitazar metabolites, these metabolites formed little to no protonated ions, and the NH4 + or Na+ adduct ions that were formed were weak and not discernible from fecal interferences even after background subtraction. With mass defect filtering on high resolution LC/MS data, the resulting total ion chromatogram and the simplified mass spectra allowed for the identification and characterization of these metabolite ions, and their structures were confirmed by synthesis.
Keywords: Mass defect filter, metabolite detection, metabolite profiling, Muraglitazar