Metabolic Profile of 6-Paradol, a Bioactive Compound of Ginger in Mice by High-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry

6-Paradol is a pungent compound found in ginger, with multiple health benefits. However, the in vivo metabolic fate of 6-paradol remains unclear, which impedes the mechanistic research and application of the compound. This is the first report of an in vivo metabolic study of 6-paradol. Herein, feces and urine samples were collected from mice after dietary administration of 6-paradol for 10 days. High-performance liquid chromatography (HPLC) coupled with quadrupole time-of-flight mass spectrometry (Q/TOF MS) was used to determine the metabolic profile of 6-paradol. A total of 32 metabolites, including 10 phase I metabolites and 22 phase II metabolites, were detected and identified based on the characteristics of their deprotonated ions. Seven phase I metabolites were chemically synthesized for definitive confirmation of their chemical structures, among which 3 compounds were reported for the first time. Our results demonstrated that 6-paradol was metabolized in vivo through demethylation, dehydroxylation, dehydrogenation, hydrogenation, carbon chain breaking, glucuronidation, sulfation, and methyl-thiolation.