Advanced Bionic Technology Combining Online Electrochemistry-Mass Spectrometry and Offline Electrochemistry-Liquid Chromatography-Mass Spectrometry for Simulating and Characterizing Metabolic Processes of Bioactive phenolic acids in Natural Products

The metabolism research of bioactive phenolic acids  widely found in natural products is of great significance for elucidating pharmacologic mechanisms and screening lead compounds. However, it is time-consuming and vulnerable to interference to conduct the traditional metabolism approach by applying organisms or biomaterials. Herein, a bionic technology was established by combining online electrochemistry-mass spectrometry (EC-MS) with offline electrochemistry-liquid chromatography-mass spectrometry (EC-LC-MS) to investigate the oxidative transformation and metabolic processes of the active phenolic acids (including salvianolic acid A, caffeic acid, 3, 5-O-dicaffeoylquinic acid, ferulic acid, salvianic acid A, and protocatechuic acid). Phase I metabolism of the phenolic acids were simulated by applying a three-electrode controlled potential electrochemical reactor with a boron-doped diamond electrode, with glutathione mixed into the oxidative products simultaneously for obtaining the phase II metabolites. Finally, structural characterization of the simulated metabolites of the phenolic acids was achieved successfully, including hydroxylation, methylation, demethylation, decarboxylation, etc. It was revealed that the simulated metabolism process based on an electrochemical system was effective in yielding a wide variety of metabolites for these compounds, which was also compared with the metabolism results applying rat liver microsomes. Consequently, this bionic technology is expected to be a powerful tool to investigate the material basis for the efficacy of active ingredients of natural products.