Analysis of the chemical constituents and rats metabolites after oral administration of Nauclea officinalis by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry

• 40 chemical constituents in Nauclea officinalis were detected by UPLC-QTOF/MS.
• 22 metabolites were identified by UPLC-QTOF/MS after oral administration of Nauclea officinalis extract.
• The proposed metabolic pathways were proposed.

Nauclea officinalis has long been used in China for the treatment of cold, fever, swelling of throat, pink eyes, and so on; however, the in vivo integrated metabolism of its multiple bioactive components remains unknown. In this paper, an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) method was established to identify chemical constituents in N. officinalis and metabolites in rat biological fluids after oral administration of N. officinalis. First, 40 chemical constituents in N. officinalis were detected within 19 min by UPLC-QTOF/MS. Among them, 18 alkaloids and 7 phenolic acids and iridoids were identified or tentatively characterized. Secondly, 22 metabolites were identified after oral administration of N. officinalis extract, including 3, 9, 6 and 4 metabolites in the plasma, feces, urine and bile samples, respectively. Finally, the metabolic pathway was proposed, which were the hydroxylation, the hydroxylation of deglycosyation product of parent compound, the hydroxylation and dehydrogenation product of parent compound, and acetylation. Among these, hydroxylation was considered as the main metabolic processes. This work suggests that the integrative metabolism approach makes a useful template for drug metabolism research of traditional Chinese medicine (TCM).