earticle

영어

The low solubility of sugars has hampered the lipase-catalyzed synthesis of fatty acid sugar esters in organic solvents and ionic liquids (ILs), because several solvents that are able to effectively dissolve sugars are detrimental to enzymes. In this work, in order to prepare a high concentration of sugars in ILs, we have developed a new procedure that entails mixing an aqueous sugar solution into ILs followed by removal of the water from the solution. The
glucose concentrations in the supersaturated [Emim][TfO] and [Bmim][TfO] were 19 and 10 times higher, respectively, than the solubility of glucose in the ILs at 25°C. Furthermore, the supersaturated glucose solutions in ILs were maintained over a long period of time without any significant loss of glucose. In ILs that were extremely supersaturated with glucose, lipase-catalyzed esterifications of glucose with vinyl laurate and lauric acid were successfully
carried out. By making the glucose concentration in ILs much higher than the solubility through our novel and simple method, the initial rate and conversion of the lipase-catalyzed reaction were significantly improved.