Enzymatic Synthesis of Arachidonic Acid-Rich Phosphatidylcholine from Arachidonic Acid Ethyl Esters

Arachidonic acid (ARA) is an essential fatty acid with numerous biological activities that benefits human health. However, ARA-rich phosphatidylcholine (PtdCho), which has a higher bioavailability than ARA-rich triacylglycerols, is scarce in the natural source. In this study, we developed an enzymatic modification approach for the synthesis of ARA-rich PtdCho from ARA-rich ethyl esters (EE). The maximum incorporation of ARA into PtdCho (24.02%) was achieved from the optimized conditions, including ARA-rich EE/PtdCho mass ratio of 2:1, hexane, lipase Novozym 435 as a biocatalyst (15% of enzyme load) and reaction time of 24 h. The 31P nuclear magnetic resonance (NMR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) results revealed that the PtdCho content decreased to 17.53% and the ARA-containing PtdCho species was primarily identified as PtdCho (18:2/20:4). Taken together, this investigation offers a new reference for the efficient production of ARA-rich PtdCho via enzymatic modification and paves a theoretical groundwork of industrial production practice.