The generation of glyceryl ether lipids highly enriched with eicosapentaenoic acid and docosahexaenoic acid by lipase

Lipase-Catalyzed Transesterification of Egg-Yolk Phophatidylcholine with Concentrate of n-3 Polyunsaturated Fatty Acids from Cod Liver Oil

Phospholipids containing PUFAs are important vehicles for their delivering to the targeted tissues. In our research project we established enzymatic methods for the enrichment of natural egg-yolk PC with n-3 PUFAs. Instead of synthetic PUFA ethyl esters, the new strategy was developed using polyunsaturated fatty acids enriched fraction (PUFA-EF) from cod liver oil as the natural acyl donors. PUFA-EF was produced by urea-complexation and contained 86.9% PUFA including 8.5% stearidonic acid (SDA; 18:4(n-3)), 26.7% EPA, and 45.2% DHA. The transesterification of PC with PUFA was catalyzed by lipases. After screening of enzymes the effect of reaction medium; molar ratio of substrates and etc. was investigated. The highest incorporation of PUFA was 45.6%; including 36.8% DHA and 5.8% EPA at the following reaction conditions: hexane; 55 °C; PUFA-EF/PC acyl ratio of 10; 48 h of reaction time and lipase B from Candida antarctica as a biocatalyst (20% of enzyme load).

Lipase-catalyzed monoesterification of 1-O-hexadecylglycerol in organic solvents

A simple method is presented to esterify 1-O-hexadecyl-rac-glycerol using lipases in different organic solvents. The following fatty acids were used: C14:0, C16:0, C18:0, C18:1, and C18:2. Monoesterification was achieved by using a limiting amount of fatty acid. Both the 1-O-hexadecyl-3-O-acylglycerol and the 2-O-acylglycerol were obtained in a total yield of 75% and a ratio 7:1 in dichloromethane after 3 d. Chromatographic data for the monoesters, useful for the identification of the natural products, are given (gas-liquid chromatography, thin-layer chromatography, reverse-phase thin-layer chromatography). The structure was confirmed by a chemical synthesis of 1-O-hexadecyl-2-O-hexadecanoylglycerol. The 3-O-glyceride was also formed by acyl migration, as the minor component. The monoesters were separated by column chromatography and characterized by 1H and 13C nuclear magnetic resonance spectra.