An Optimized and Sensitive UHPLC-ESI-Q-TOF/HRMS Demonstrated the Dynamic Profiling of Allantoin,...

This study revealed the dynamic profiling of three main components of Portulaca oleracea L. in vivo in rats, namely allantoin (A), N-trans-feruloyl-3-methoxytyramine (M), and N-p-coumaroyltyramine (C). A sensitive and efficient UHPLC-ESI-Q-TOF/HRMS, including an optimized separation process, was applied to their qualitative and quantitative analysis. The validation of the method presented the correlation coefficients, which were over 0.997. The mean matrix factors were 0.930. Recoveries ranged from 96.6% to 109.2%, and determination accuracy varied from 95% to 109.4%. The biological samples included rat plasma, liver, kidneys, bile, and excreta taken after a single oral administration of the saturated DMSO solution of P. oleracea extract. The contents of A, M, and C were of 2.5, 5.1, and 3.4 g/kg in the dry whole herb, respectively. A was identified in the liver and kidneys from 0 to 6 h. Allantoic acid, as one metabolite of A, was found to be kept in plasma for a short time, but another two successive metabolites of A remained over 6 h. It depicted a pharmacological material basis of the herb, regarded with A. The glucuronidation and/or sulfation of M and C were detected in rat bile from 0 to 12 h. The complicated but interesting metabolic schemes for A, M, and C were illustrated from their HRMS and MS/MS performance.