ENZYMATIC-SYNTHESIS OF PHOSPHATIDYLCHOLINE WITH FATTY-ACIDS, ISOOCTANE, CARBON-DIOXIDE, AND PROPANE AS SOLVENTS

Phosphatidylcholine (PC) was synthesized from lyse-PC and long polyunsaturated fatty acids (PUFA) with phospholipase A(2). In previous investigations, performed in small glass tubes, the enzymatic synthesis reaction was optimized. This paper presents results from experiments performed in a high-pressure reactor filled with an immobilized enzyme (Im.E.). Fatty acids were used as the main solvent while isooctane, CO2, or propane was used as an additional solvent. The water content was carefully controlled over wide ranges. The temperature was kept constant at 45 degrees C for up to 50 h. The highest initial reaction rate was attained with pure fatty acids under relatively humid conditions (water = 35% of dry Im.E.). The reaction rates were more than three times as high in the high-pressure reactor than in previous experiments in glass tubes. In all solvent systems, the best yield was attained after long times under dry conditions (water <15% of dry Im.E.). Addition of CO2 to the PUFA reduced the yield, while addition of isooctane or propane increased the yield. After 20 h at 45 degrees C, the best yield (25%) was attained at a solvent composition of 91% PUFA and 9% propane.