Novel deep eutectic solvents promote enzyme-substrate molecular dynamic adaptation to enhance sucrose ester synthesis...

The eco-friendly synthesis of sucrose esters represents a critical technological advancement for the food and pharmaceutical sectors, where conventional chemical methods face persistent challenges including insufficient selectivity, economic inefficiency, and environmental concerns. To overcome these limitations, we developed an enzymatic synthesis platform utilizing a novel deep eutectic solvent (DES) system comprising cyclohexanone:lauric acid:pyridine, which facilitates the dynamic molecular adaptation between the enzyme and bulky substrates. Through systematic optimization, a remarkable sucrose ester yield of 98.21 % was achieved under the identified conditions (substrate molar ratio of 1:6, enzyme addition of 0.1 g, used cyclohexanone, lauric acid, and pyridine as the medium, reaction at 60 °C in 72 h). Density functional theory (DFT) analysis confirmed the formation of extensive hydrogen bonds between pyridine and lauric acid, validating the successful establishment of this novel DES. The molecular dynamics simulations (MD) elucidated that cyclohexanone and lauric acid-maintained enzyme structural stability and beneficial to the anchoring of substrates, while the introduction of pyridine moderately increases the flexibility of the enzyme's active site, optimizes the substrate-binding pocket size, and enhances dynamic adaptation with large substrates such as sucrose, achieving a balance between activity and stability. This study provides a new approach for the rational design of enzymatic catalytic systems.