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Updated: Jun 24, 2026

Liquid Chromatography Coupled to Refractive Index or Mass Spectrometric Detection for Metabolite Profiling in Lysate-based Cell-free Systems
Published on: September 23, 2021
Mass defect filtering on high resolution LC/MS data as a methodology for detecting metabolites with unpredictable
Donglu Zhang1, Peter T Cheng, Haiying Zhang
1Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research & Development, Princeton, NJ 08543, USA.
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 NH(4)(+) 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.

