An efficient resolution of racemic secondary alcohols on magnetically separable biocatalyst

The combination of magnetic nanoparticles and mesoporous silica can present a strategy for enzyme immobilization. In this work, magnetic siliceous mesocellular foam functionalized with octyl groups was prepared and used as support for lipase adsorption. Almost all the active lipases in crude enzyme solution were adsorbed by this magnetically separable, hydrophobic siliceous mesocellular foam. The resolution of 1-phenylethanol acylated with vinyl acetate can be achieved in 1.5 h using the resultant magnetic biocatalyst, whereas only 30% conversion was obtained by using the free lipase under the identical reaction conditions. These results are probably due to the interfacial adsorption and hyper-activation of lipase on the hydrophobic surface of the magnetic siliceous mesocellular foam. Moreover, the biocatalyst entrapped in the nanopores of this foam can be recycled magnetically for at least seven times without significant loss of its activity and enantioselectivity. (c) 2007 Elsevier Inc. All rights reserved.