Biodegradation of Punicalagin into Ellagic Acid by Selected Probiotic Bacteria: A Study of the Underlying Mechanisms by MS-Based Proteomics

• DOI: 10.1021/acs.jafc.2c06585
• Publication Date: 2022-12-15T07:38:57Z
• Authors: Víctor Caballero; Mario Estévez; Francisco A. Tomá...; David Morcuende; Irene Martín; Josué Delgado
• Keywords: Punicalagin; 3107.04 Fruticultura; Proteomics; Urolitina; Ellagic acid; 0303 health sciences; Bacteria; Plant Extracts; Proteómica metabolómica; Ácido elágico; Punicalagina; Hydrolyzable Tannins; Bacterias del ácido láctico; Urolithin; Anthocyanins; 03 medical and health sciences; 2302.90 Bioquímica de Alimentos; Ellagic Acid; Phenols; Lactic acid bacteria; Proteomics metabolomics

Pomegranate (Punica granatum L.) is a well-known source of bioactive phenolic compounds such as ellagitannins, anthocyanins, and flavanols. Punicalagin, one of the main constituents of pomegranate, needs to be biodegraded by bacteria to yield metabolites of medicinal interest. In this work, we tested 30 lactic acid bacteria (LAB) and their capacity to transform punicalagin from a punicalagin-rich pomegranate extract into smaller bioactive molecules, namely, ellagic acid and urolithins. These were identified and quantified by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS2). Further, we evaluated the molecular mechanism governing this transformation through label-free comparative MS-based proteomics. All tested LAB strains were capable of transforming punicalagin into ellagic acid, while the biosynthesis of urolithins was not observed. Proteomic analysis revealed an increase of generic transglycosylases that might have a hydrolytic role in the target phenolic molecule, coupled with an increase in the quantity of ATP-binding cassette (ABC) transporters, which might play a relevant role in transporting the resulting byproducts in and out of the cell.