Solubility of curcuminoids in natural deep eutectic solvents

Pure natural deep eutectic solvents (NADESs) and aqueous NADESs are used as state-of-the-art combinatorial solvents for the solvation of three curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. A priori selection strategy has been employed to determine the best possible DES for curcuminoids as the DESs are constituted in various molar ratios of 10 hydrogen bond acceptors (HBAs) and 31 hydrogen bond donors (HBDs). Hence, a conductor-like screening model segment activity coefficient (COSMO-SAC) based formulation has been implemented to estimate the logarithmic infinite dilution activity coefficient and, subsequently, the solubility of curcuminoids among 75 NADESs and 27 aqueous NADESs. The effects of the composition of DESs, temperature, and the effect of water have thoroughly been revealed.