Tuning toxic properties of polyethylene glycol-based deep eutectic solvents for achieving greener solvents

Low toxicity is one of the key properties for the sustainable application of polyethylene glycol-based deep eutectic solvents (PEG-based DESs) in separation, catalysis, biochemistry and analysis. However, the tox-icity of PEG-based DESs is not reported and the rules for obtaining lower toxicity is needed to explore. Herein, the cytotoxicity of several PEG-based DESs against lung cancer cell (A549) was evaluated by CCK-8 assay, and strategies for the minimizing and tuning the toxicity of DESs are for the first time pro-posed from the aspects of mole ratio, hydrogen-bonding donor, hydrogen-bonding acceptor, components numbers, and solvent concentration. The results indicated that the DESs are more toxic than their indi-vidual components, and the toxicity order of DESs is generally in accordance with the individual compo-nents except for the hydrogen-bonding donor. This work would provide possible routes for the decrease of DESs toxicity for sustainable and green chemistry. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Low toxicity is a crucial property for the sustainable use of polyethylene glycol-based deep eutectic solvents (PEG-based DESs) in various fields. However, the specific toxicity of PEG-based DESs has not been reported, and guidelines for reducing toxicity need to be explored. This study evaluated the cytotoxicity of several PEG-based DESs against lung cancer cells (A549) and proposed strategies for minimizing toxicity, such as adjusting mole ratio, hydrogen-bonding donor, hydrogen-bonding acceptor, components numbers, and solvent concentration. The results showed that DESs are more toxic than their individual components, generally following the toxicity order of the individual components, except for the hydrogen-bonding donor. This research offers potential approaches for reducing the toxicity of DESs in sustainable and green chemistry.