Substrate selectivity and optimization of immobilized SMG1-F278N lipase in synthesis of propylene glycol monooleate

In the present study, the immobilized SMG1-F278N lipase was employed for the esterification of 1,3-propylene glycol with oleic acid. This was the first report of using mono- and diacylglycerol lipase for the production of propylene glycol monoesters (PGME). It was found that immobilized SMG1-F278N preferred 1,3-propylene glycol than 1,2-propylene glycol. Molecular docking of 1,2-propylene glycol and 1,3-propylene glycol into SMG1-F278N suggested that the 1,3-propylene glycol preferentially binds to the active pocket of SMG1-F278N as compared to 1,2-propylene glycol. The maximum 1,3-propylene glycol monooleate content of 70.67% was obtained under the reaction conditions of 1,3-propylene glycol/oleic acid ratio of 5:1 (mol/mol), enzyme loading of 7.5% (w/w, with respect to total substrates), and water addition of 7% (w/w, with respect to total substrates) at 30°C. The present work offers insights into the selectivity of immobilized SMG1-F278N towards 1,2-propylene glycol and 1,3-propylene glycol, and suggests the extended applications of immobilized SMG1-F278N for industrial purpose. Practical applications: To our knowledge, the production of PGME using mono- and diacylglycerol lipases was reported for the first time. This study could contribute to develop potential applications of immobilized SMG1-F278N in industries. 1,2-Propylene glycol/1,3-propylene glycol docked into the catalytic pocket of SMG1-F278N, esterification of 1,2-propylene glycol/1,3-propylene glycol with oleic acid catalyzed by immobilized SMG1-278N and optimization of production of 1,3-propylene glycol monooleate.