Assessment of cytotoxicity of choline chloride-based natural deep eutectic solvents against human HEK-293 cells: A QSAR analysis.

Deep eutectic solvents (DESs) are a new generation of solvents. To consider them as green solvents, investigation of their toxicity is essential. In this work, the cytotoxicity of a number of natural deep eutectic solvents (NADESs) against HEK-293 human embryonic kidney cells was evaluated by MTT assay. The NADESs were prepared with choline chloride (ChCl) as hydrogen-bond acceptor (HBA) and different sugar alcohols as hydrogen-bond donor (HBD) constituents. They showed IC50 values in the range of 3.52-75.46 mM. These results were used to evaluate the effect of structural parameters on the cytotoxicity of the studied NADESs by using quantitative structure activity relationship (QSAR) analysis. A three-parameter linear model was obtained between - log(IC50) as a dependent variable and structural descriptors as independent variables. Rotatable bond number (RBN), mean atomic van der Waals volume (Mv) and the interaction of second power carbon numbers with the molar ratio of HBA to HBD in each NADES (C2 Ratio), were three major parameters. The statistical model covered about 76.4% and 69.8% variance of data in training and leave-one-out cross-validation, respectively. This work, as the first study on the QSAR analysis of DESs, can provide a good perspective for designing greener novel DESs.