Enzymatic Reaction in Organic Solvents and Supercritical Gases

Abstract

The enzymatic esterification of glycidol and butyric acid, catalysed by porcine pancreatic lipase (ppl), has been performed in different organic solvents and compared with equilibrium conversions estimated from theory. Preliminary results show that the predicted equilibrium conversions were in good agreement with experiments for most of the organic solvents tested. In different organic solvents the enzyme exhibited enantioselectivity. It appears that the more polar the organic solvent, the higher was the selectivity towards the R-isomer. Conversions were also predicted for supercritical solvents. The conversion in supercritical carbon dioxide was predicted to be greater than that in the organic solvents. Moreover, the conversion in carbon dioxide was predicted to be greater than that in supercritical ethane. In the phase behavior of the glycidol and carbon dioxide binary two liquid phase coexisted near the critical point of pure carbon dioxide. Taking into account the three phase (liquid-liquid-vapor) lines of glycidol-carbon dioxide, the gas phase reaction conditions should be selected at temperatures above 310 K and pressures above 80 bar.