Synthesis of phospholipids containing polyunsaturated fatty acids by phospholipase A(2)-mediated esterification with food-compatible reagents.

Enzymatic synthesis of phospholipids (PLs) containing polyunsaturated fatty acids (PUFAs) was studied. The main purpose was to establish an efficient production method for PLs containing docosahexaenoic acid or eicosapentaenoic acid using only food-compatible reagents. Phospholipase A(2) (PLA(2))-mediated ester synthesis was employed to introduce the PUFAs into the sn-2 position of lysophospholipid (LPL) to yield PUFA-containing PLs. When LPL and the fatty acids were reacted in glycerol in the presence of porcine pancreas PLA(2), the reaction was not very effective. However, it was found that addition of certain kinds of amino acids such as glycine or L-alanine in the reaction mixture improved the reaction. After the reaction, the synthesized PLs were extracted selectively with ethanol and n-hexane, leaving the unreacted LPL, amino acids and the enzyme remained in the glycerol layer. It was confirmed that the enzyme remained in the glycerol layer could be reused by adding fresh substrates for the subsequent reactions.