Identification of poliumoside metabolites in rat feces by high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry

• An HPLC/Q-TOF-MS method was developed for metabolite identification.
• Sixty-six metabolites of poliumoside were detected in rat feces.
• Poliumoside could be partly transformed into isopoliumoside in vivo.
• The major metabolic soft spots of poliumoside were identified.
• Proposed major metabolic pathways of poliumoside in rats were summarized.

Poliumoside is one of the major phenylethanoid glycosides (PhGs) isolated from Callicarpae Caulis et Folium (CCF) which is a traditional Chinese medicine used for hemostasis in clinic. In this study, high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (HPLC/Q-TOF-MS) was applied to investigate the metabolites of poliumoside in rat feces after oral administration. A total of 66 metabolites were confirmed or tentatively identified. Poliumoside could be partly transformed into its positional isomer isopoliumoside in vivo, and poliumoside was easily hydrolyzed and metabolized into degradation products. The parent compound and its degradation products could further undergo extensive phase I and phase II metabolism. The results indicated that hydrolysis, hydroxylation, acetylation, sulfation, hydration, reduction, dehydrogenation and dimethylation were the major metabolic pathways of poliumoside. The major metabolic soft spots of poliumoside and the fragmentation patterns of the metabolites were also proposed. This study provided valuable information regarding the metabolites of poliumoside in rats.