Use of Ionic Liquids in the Enzymatic Synthesis of Structured Docosahexaenoic Acid Lyso-Phospholipids

Abstract

Recent studies have shown that DHA supplementation in the form of phospholipids effectively increases DHA levels in the brain, including DHA lysophospholipids. This research explores a method to produce DHA lysophosphatidylcholine (DHA-LPC) using lipases and phospholipases immobilized on Immobeads-C18 with maximal enzyme loading. The esterification of glycerophosphatidylcholine (GPC) and DHA was studied with ionic liquids as alternatives to traditional solvents, with 1-methyl-3-octylimidazolium tetrafluoroborate (MOIM-BF4) providing the highest yield due to its ability to increase the solubility of GPC. The reaction parameters were modified to establish a molar ratio of GPC to DHA of 1/10. A maximum DHA-LPC yield of 80% was achieved in 48 h, with a formation rate of 20.06 (mg/mL.h) × g. The Quara® LowP biocatalyst (QlowP-C18) maintained 100% activity during the first three cycles and produced 788 mg of DHA lysophospholipid. The use of 50% MOIM-BF4 improved the stability of the biocatalyst, and NMR confirmed that the product was the sn1-DHA-LPC isomer.