title: Enzyme catalysis in organic solvents: influence of water content, solvent composition and temperature on Candida rugosa lipase catalyzed transesterification.
abstract: In the present study the influence of water content, solvent composition and reaction temperature on the transesterification of 1-phenylpropan-2-ol catalyzed by Candida rugosa lipase was examined. Reactions were carried out in different mixtures of hexane and tetrahydrofurane. The studies showed that an increasing water content of the organic solvent results in an increasing enzyme activity and a decreasing enantiomeric excess. Furthermore, a significant influence of the solvent hydrophilicity both on the enzyme activity and on the enantiomeric excess was found. An increase in solvent hydrophilicity leads to a decrease of enzyme activity and an increase of the enantiomeric excess. This indicates that the enzyme becomes more selective with decreasing flexibility. Similar effects were found by variation of the reaction temperature. Taken together, the decrease in conversion and the increase in selectivity with increasing solvent hydrophilicity are induced by the different water contents on the enzyme surface and not by the solvent itself.
authors.affiliation: Helmut Schmidt University/University of Federal Armed Forces Hamburg, Process Engineering, D-22043 Hamburg, Germany. dherbst@hsu-hh.de
authors.forename: Daniela
authors.initials: D
authors.lastname: Herbst
authors.forename: Stephanie
authors.initials: S
authors.lastname: Peper
authors.forename: Bernd
authors.initials: B
authors.lastname: Niemeyer
mesh_terms: D019149:Bioreactors; D002175:Candida / Q000201:enzymology*; D004951:Esterification; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D005663:Furans / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D020005:Propanols / Q000737:chemistry / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D005663:Furans; D006586:Hexanes; D020005:Propanols; D012997:Solvents; D014867:Water; C439395:1-phenylpropanol; D008049:Lipase