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Preparation of phospholipids highly enriched with n‐3 polyunsaturated fatty acids by lipase
Author(s) -
Haraldsson Gudmundur G.,
Thorarensen Atli
Publication year - 1999
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-999-0087-2
Subject(s) - phosphatidylcholine , lipase , chemistry , polyunsaturated fatty acid , docosahexaenoic acid , transesterification , eicosapentaenoic acid , hydrolysis , triacylglycerol lipase , phospholipid , chromatography , organic chemistry , lysophosphatidylcholine , phosphatidic acid , rhizomucor miehei , fatty acid , biochemistry , methanol , enzyme , membrane
The immobilized 1,3‐regiospecific Rhizomucor miehei lipase (Lipozyme™) was employed to catalyze the transesterification reaction (acidolysis) of 1,2‐diacyl‐ sn ‐glycero‐3‐phosphatidylcholine with n‐3 polyunsaturated fatty acids under nonaqueous solvent‐free conditions. With a concentrate of 55% eicosapentaenoic acid (EPA) and 30% docosahexaenoic acid (DHA) and pure phosphatidylcholine from egg yolk, phospholipids of 32% EPA and 16% DHA content were obtained, presumably as a mixture of phosphatidylcholine and lysophosphatidylcholine. 31 P nuclear magnetic resonance (NMR) analysis turned out to be a valuable technique to study the details of the reactions involved. It revealed that when 1,2‐dipalmitoyl‐ sn ‐glycero‐3‐phosphatidylcholine was transesterified with 98% pure EPA, a substantial amount of hydrolysis side reaction took place (39%), leading to a product mixture of 39% phosphatidylcholine, 44% lysophosphatidylcholine, and 17% sn ‐glycerol‐3‐phosphatidylcholine. The lysophosphatidylcholine constituent comprised 70% EPA, whereas the phosphatidylcholine component contained 58% EPA. The 31 P NMR technique provided valid information about the mechanism of the reaction. It became evident that a high dosage of lipase containing 5% water afforded optimal conditions for the optimal extent of EPA incorporation into the phospholipids, under which the extent of hydrolysis side reaction remained relatively high.