Immobilized Hydroxynitrile Lyases for Enantioselective Synthesis of Cyanohydrins: Sol‐Gels and Cross‐Linked Enzyme Aggregates

Abstract

AbstractThe hydroxynitrile lyases (HNLs) from Prunus amygdalus (PaHNL), Manihot esculenta (MeHNL), and Hevea brasiliensis (HbHNL) were successfully immobilized in sol‐gels. The cross‐linked enzyme aggregate (CLEA) of HbHNL was also prepared. These immobilized enzymes and the commercial PaHNL‐ and MeHNL‐CLEAs were employed for the enantioselective synthesis of cyanohydrins. The sol‐gels were highly efficient at low catalyst loading and particularly stable towards the organic solvent (diisopropyl ether) and substrate/product deactivation. The stabilization effect was inconsistent for CLEAs of different HNLs and significant deactivation of PaHNL‐ and HbHNL‐CLEAs in diisopropyl ether was observed. In contrast commercial MeHNL‐CLEA proved to be a remarkably robust and efficient biocatalyst in diisopropyl ether.