Chymotrypsin-Catalyzed Transesterification in Ionic Liquids and Ionic Liquid/Supercritical Carbon Dioxide

The potential utility and versatility of biotransformations in ionic liquids and ionic liquids mixed with supercritical carbon dioxide is demonstrated using a model enzyme reaction. The characteristics of enzyme activity in the ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate and 1-octyl-3-methylimidazolium hexafluorophosphate are consistent with those observed in conventional organic solvents. The presence of supercritical carbon dioxide modifies the properties of ionic liquids, altering the conditions required for optimum enzyme activity. These findings indicate that the combination of ionic liquids with supercritical carbon dioxide may represent a particularly efficacious medium for clean non-aqueous biosynthesis.