HeT ellagitannin isolated from strawberry leaves is oxidized by interacting with cell membranes

MARTOS, GUSTAVO GABRIEL; ABATE, PEDRO O.; KATZ, NÉSTOR E.; DIAZ-RICCI, JUAN CARLOS

Congreso; XXXIV Jornadas Científicas de la Asociación de Biología de Tucumán; 2017

Previous studies have shown that the bioactivity of certain polyphenols and compounds extracted from plants such as totarol, abietic acid and resveratrol is due to the fact that they produce important disturbances in the phospholipid membranes. Our group has earlier reported the isolation of an ellagitannin (1-0-galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-β-D-glucopyranose, HeT) from strawberry leaves, capable of activating the immune response in plants. It has recently been shown that HeT also has antimicrobial activity. The objective of this work was to investigate the possible interaction of HeT with cell membranes (CM). To this end, different assays were performed on cell membranes isolated from Clavibacter michiganensis. Using Raman and FT-IR spectroscopy (2000-600 cm-1), we observed a strong interaction among the major HeT groups with CM. It was also observed that the interaction between HeT and CM caused changes in the UV-Visible spectrum of the ellagitannin, producing three new bands at 360nm, 440nm and 490nm. The electrochemical analysis by Differential Pulse Voltametry indicated that HeT is oxidized to a potential of V = + 0.164V vs. Ag/AgCl. Subsequently, a spectroelectrochemical study was performed (V = +0.3) and the spectrum change obtained showed the same three bands observed in the