Antimicrobial, antioxidant, and toxicity assessment of Ammonium-Based deep eutectic solvents with formic acid and butyric acid hydrogen bond donors

Abstract

An investigation on the toxicological assessment of tetrabutylammonium bromide (TBABr)-based deep eutectic solvents (DESs) with formic acid (FA) and butyric acid (BA) towards bacteria, fungi, Cyrinus Carpio fish, and mouse fibroblast cell line was performed. A homogenous mixture of DESs was formulated by heating at 60 °C for 20 min which was further analyzed by Fourier Transform Infrared Spectroscopy (FTIR). In FTIR, a significant difference was found in the absorbance of DESs and their precursors. Among tested DESs, TBABr: FA exhibited maximum zone of inhibition towards tested bacterial strains in comparison to TBABr: BA. While TBABr: BA was found to be more effective against both fungal strains than TBABr: FA. TBABr: FA had a higher lethal concentration at 50% (LC50) than TBABr: BA against Cyprinus carpio fish. Both DESs were found to have a higher % of cell viability at higher concentrations while a gradual decline was observed with a decrease in concentration. However, both DES had ∼50% of the DPPH scavenging activity in comparison to standard (ascorbic acid). In conclusion, both DESs had been successfully formed and were found less harmful at their higher concentrations, thus can be used as promising solvents in the future.