Characterization of TPN171 metabolism in humans via ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

This study aimed to establish a rapid and reliable method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry for the characterization of TPN171 metabolites in human plasma, urine and stool samples. A total of 17 metabolites, including 14 from phase I and 3 from phase II metabolic reactions, were identified and characterized. TPN171 was found to be the predominant component in all plasma, urine and stool samples. Seven proposed metabolites were validated by comparing with synthetic reference standards. N-demethylation, O-depropylation, N-oxidation and dehydrogenation were demonstrated to be the main metabolic pathways of TPN171 in humans, yielding metabolites M4, M3, M7-2 and M5-3, respectively. Notably, M5-3 (a dehydrogenation product) and M3 (an O-depropylation product) were the main metabolites in human plasma while M5-3 (produced via dehydrogenation) and M7-2 (produced via N-oxidation) were the major metabolites in human urine. Besides, O-depropylation product M3 and N-demethylation product M4 were the main metabolites in human stool. In overall, this study assessed the metabolic fate of TPN171 in humans, which may yield considerably benefits for subsequent studies focusing on TPN171 metabolism and development of other PDE5 inhibitors.Graphical abstract
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research