Molecular docking simulation reveals the lipase–substrate binding mechanism in the enzymatic synthesis of diacylglycerol-enriched vegetable oils

Diacylglycerol (DAG) is a functional lipid that is naturally present in vegetable oils in limited concentrations (1 %–5 %). This study proposed an enzymatic method to afford high-content-DAG vegetable oils via a reaction catalyzed by an immobilized lipase, PS@OMS-C₈, using high-speed homogenization and molecular distillation. Results indicated that 48.6 % DAG was initially obtained through the enzymatic glycerolysis of rapeseed oil with glycerol, of which 90.2 % was sn-1,3-DAG. PS@OMS-C₈ maintained 35.5 % DAG content after 10 reuse cycles, confirming its catalytic stability; this was attributed to lipase immobilization on the ordered mesoporous silica that significantly improve the secondary protein structures, including α-helix and β-sheet, thereby strengthening the rigidity of PS@OMS-C₈. In addition to producing DAG-enriched rapeseed oil, other edible oils with 39.4 %–50.2 % DAG content were obtained, as revealed via molecular docking simulation. This study offers new strategies for the sustainable synthesis of vegetable oils with a high content of functional lipids high-content functional lipids.