Rapid screening and characterization of caffeic acid metabolites in rats by UHPLC-Q-TOF mass spectrometry

Abstract

Purpose: To determine the metabolism of caffeic acid in rats. Methods: Sprague-Dawley rats were intragastrically administered caffeic acid in saline suspension, and biological samples collected. After sample pretreatment by solid phase extraction, ultra-high performance liquid chromatography combined with quadrupole-time of flight mass spectrometry system (UHPLC-Q-TOF-MS/MS) was established to rapidly screen and characterize caffeic acid metabolites in rats. Waters HSS T3 UPLC chromatographic column (2.1 mm × 100 mm, 1.7 μm) was applied for the gradient elution with aqueous solution of formic acid (A)-acetonitrile (B). Mass spectral data for the biological samples in electrospray positive and negative ion modes were collected and analyzed by SCIEX OS 1.3 workstation. Results: Based on their precise molecular weights and multistage mass spectrometry cleavage information, caffeic acid and 21 metabolites in vivo were identified. The results demonstrate that the biotransformation of caffeic acid in vivo was mainly achieved via hydrogenation, hydroxylation, methylation, sulfonation, glucuronidation, acetylation, and composite reactions. Conclusion: The metabolites and metabolic pathways of caffeic acid in rats have been rapidly elucidated, and its potential pharmacodynamics forms have been clarified. This provides a valuable and meaningful reference for the study of caffeic acid metabolites, biological activities, and its medicinal material basis in vivo.