Covalent organic framework immobilized lipase for efficient green synthesis of 1, 3-dioleoyl-2-palmitoylglycerol

Abstract

The covalent organic framework TPB-DMTP-COF was synthesized (TPB was 1, 3, 5-tris (4-aminopHenyl) benzene. DMTP was 2, 5-dimethoxybenzene-1, 4-dicarbaldehyde). Lipase from Rhizomucor miehei (RML) was covalently immobilized in the covalent organic framework (COFs) giving the composite TPB-DMTP-COF@RML. The novel immobilized enzyme were applied to achieve efficient synthesis of 1, 3-dioleoyl-2-palmitoylglycerol (OPO structured lipids). The immobilization efficiency of TPB-DMTP-COF @ RML was 65 %, and the expression activity was 165 U/g. The characterization of FT-IR, XRD, SEM and CLSM proved the successful preparation of COFs materials and the immobilized lipase TPB-DMTP-COF@ RML. After 21 days of storage at room temperature(25 °C), the immobilized lipase maintained 77.53% of the original activity, while the free enzyme was only 52.96 %. After 7 times of repeated use, the relative activity of 68.97 % was maintained. 1, 3-dioleoyl-2-palmitoylglycerol(OPO) was synthesized by enzymatic hydrolysis of tripalmitin and oleic acid under the action of TPB-DMTP-COF @ RML biocatalyst.The highest content of OPO structural grease is 44.71 %, which provides a good reference for the green production of OPO structural grease.