Objective To investigate the metabolic routes and metabolites of Rehmannia glutinosa and Cornus officinalis herb pair produced by gut microbiome from rats.Methods A rapid and sensitive ultra-performance liquid chromatography/quadrupole-time-offlight mass spectrometry(UPLC-Q-TOF/MS) technique combined with Metabolynx?software was established and successfully applied to identify the metabolites of the main bioactive components in the herb pair extract by rat intestinal bacteria.Results Four parent compounds(loganin,morroniside,catalpol,and acteoside) and their eight corresponding metabolites were detected and tentatively identified by the characteristics of their protonated ions.Hydrogenated and demethylated loganetin,dehydroxylated morronisid aglycone,caffeic acid,and its methylated product were the main metabolites.These metabolites suggested that the glycosides were firstly hydrolyzed to their aglycones by hydrolytic enzymes of the enteric microbial flora and subsequently to the other metabolites through hydrogenation,(de)-methylation,and de-hydroxylation.Conclusion The results may be helpful for the further investigation of the pharmacokinetic study of R.glutinosa and C.officinalis herb pair in vivo.
