Metabolite profiles of epimedin B in rats by ultraperformance liquid chromatography/quadrupole-time-of-flight mass spectrometry

In this work, the metabolite profiles of epimedin B in rat feces, bile, urine, and plasma were qualitatively investigated, and the possible metabolic pathways of epimedin B were subsequently proposed. After oral administration of epimedin B at a single dose of 80 mg/kg, rat biological samples were collected and pretreated by protein precipitation. Then, these pretreated samples were injected into an Acquity ultraperformance liquid chromatography BEH C₁₈ column with mobile phase consisting of 0.1% formic acid-water and 0.1% formic acid-acetonitrile and detected by ultraperformance liquid chromatography/quadrupole-time-of-flight mass spectrometry. In all, 43 metabolites were identified in the biosamples. Of these, 13, including F5, F7, F16-F18, D5-D7, D9, N5, N7, M1, and M3, were to our knowledge reported for the first time. The results indicated that epimedin B was metabolized via desugarization, dehydrogenation, hydrogenation, hydroxylation, demethylation, glucuronidation, and glycosylation pathways in vivo. Specific hydrolysis of 7-O-glucosides in the gut lumen and glucuronic acid conjugation in the liver were considered as the main physiologic processes of epimedin B. This study revealed the possible metabolite profiles of epimedin B in rats.