Enzymatic Catalysis in Buffered Ionic Liquids pp. 437-454
Authors: (Guangnan Ou, School of Bioengineering, Jimei University, China)
Abstract: Many chemical reactions are sensitive to pH values, that is, the yield of products and even the nature of the products may be altered appreciably if the pH changes significantly during the process of reaction. This is especially true in biochemical reactions where the
pH is important to the proper metabolism and functioning of animals and plants. We can efficiently control the pH of an aqueous media at a predetermined level by the addition of water-soluble buffer substances. In non-aqueous media, common buffers were found to
have only limited solubility, therefore, reactions in non-aqueous media have been investigated without controlling the pH of the system. To overcome this restriction, we have designed and synthesized a new class of ionic liquid (IL) with buffering behaviour
that are referred to as IL buffers, which are miscible with polar solvents such as methanol, DMF, and dichloromethane and also with ILs like [BMIM][PF6] and [BMIM][BF4]. For the development of buffered enzymatic ionic liquid systems, ionic liquid buffer having phosphate anion was synthesized. The effects of IL and buffer on activity and stability of Candida antarctica lipase B (CALB) were investigated using the transesterification of ethyl butyrate with n-butanol as a model reaction.