Lipases in green chemistry: Deep eutectic solvents (DES) as new green solvents

Abstract

Deep eutectic solvents (DES) may become important alternatives as versatile, biodegradable, and costeffective solvents for biocatalysis. Especially for reactions where substrates and products of different polarities are combined, the design of a tailored solvent that may dissolve all compounds—while being enzyme-compatible at the same time—appears to be a strong ally in sustainable chemistry. Herein it is shown that the combination of DES with “water as cosolvent” (in a range from 5% to 20% water, v/v) leads to non-conventional solvents with significantly reduced viscosity. In these media, lipases and proteases can perform synthetic reactions efficiently, and hydrolytic side reactions remain suppressed (even at 20% water, v/v). The use of these less viscous non-conventional media could also provide options for hydrolasecatalyzed synthetic reactions even in continuous fashion.