The Metabolism Study of Oleraisoquinoline in Rats Using Ultrahigh-performance Liquid Chromatography-electrospray Coupled with Quadrupole Time-of-flight Mass Spectrometry and its Bioactivities

This study aimed to investigate the main metabolites and metabolic pathways of oleraisoquinoline in rats, a new alkaloid isolated from Portulaca oleracea L., and test its antioxidation and anticholinesterase effects Ultra-high-performance liquid chromatography-electrospray coupled with quadrupole time-of-flight mass spectrometry (UHPLC-ESI-Q-TOF/MS) was applied to study the metabolism of oleraisoquinoline. Furthermore, 1,1‑diphenyl‑2‑picrylhydrazyl assay and modified Ellman’s method were used to test the antioxidation and anticholinesterase effects of oleraisoquinoline, respectively The metabolism results of oleraisoquinoline showed, after its administration through the tail vein of rats, 4 metabolites in the plasma samples, 17 metabolites in the urine sample, and 2 metabolites in the feces sample. The main metabolic pathways were hydrolyzation, oxidation, hydroxylation, sulfonation, glucuronidation, acetylation, and methylation. Additionally, IC50 values of antioxidant and anticholinesterase activities were 13.819 ± 0.005 µM and 10.551 ± 0.069 µM, respectively. 21 metabolites were found in the rat’s plasma, urine, and feces samples, and the metabolic pathways included hydrolyzation, oxidation, hydroxylation, sulfonation, glucuronidation, acetylation, and methylation; among them, sulfonation was the main metabolic reaction. Meanwhile, oleraisoquinoline also showed extremely good antioxidant and anticholinesterase activities.