Enzymatic preparation of a sciadonic acid-enriched phospholipid fraction and its in-vitro lipid-accumulation-inhibitory effect.

Sciadonic acid (SCA) is an unusual Δ5 polyunsaturated fatty acid reported to affect lipid metabolism and inflammation. Because phospholipid forms of bioactive fatty acids may improve bioavailability and modify biological activity, this study prepared SCA-enriched phospholipid fractions. SCA ethyl ester (SCA-EE) derived from Torreya grandis seed oil was transesterified with phosphatidylcholine (PC) in [C₄MIM]Tf₂N using Novozym 435. Under optimized conditions (PC/SCA-EE molar ratio 1:7, 20% enzyme loading, 55 °C, 24 h), SCA incorporation into the purified PC fraction reached 25.96%, as determined by GC/FID. Molecular docking and FTIR were used to investigate possible lipase-substrate interactions and lipase secondary-structure changes in ionic-liquid systems, respectively. In an oleic-acid-induced HepG2 model, the SCA-enriched phospholipid fraction inhibited intracellular lipid accumulation more strongly than PC and SCA-EE at the tested mass doses. These results support ionic-liquid-assisted enzymatic transesterification as a feasible laboratory-scale approach for preparing SCA-enriched phospholipid fractions with improved lipid-accumulation-inhibitory activity.