The technological utility of enzymes can be enhanced greatly by using them in organic solvents rather than their natural aqueous reaction media. Studies over the past 15 years have revealed not only that this change in solvent is feasible, but also that in such seemingly hostile environments enzymes can catalyse reactions impossible in water, become more stable, and exhibit new behaviour such as 'molecular memory'. Of particular importance has been the discovery that enzymatic selectivity, including substrate, stereo-, regio- and chemoselectivity, can be markedly affected, and sometimes even inverted, by the solvent. Enzyme-catalysed reactions in organic solvents, and even in supercritical fluids and the gas phase, have found numerous potential applications, some of which are already commercialized.

Improving enzymes by using them in organic solvents

Roger Sheldon (1942) received a PhD in organic chemistry from the University of Leicester (UK) in 1967. This was followed by post-doctoral studies with Prof. Jay Kochi in the U.S. From 1969 to 1980 he was with Shell Research in Amsterdam and from 1980 to 1990 he was R&D Director of DSM Andeno. In 1991 he moved to his present position as Professor of organic chemistry and catalysis at the Delft University of Technology (The Netherlands). His primary research interests are in the application of catalytic methodologies—homogeneous, heterogeneous and enzymatic—in organic synthesis, particularly in relation to fine chemicals production. He developed the concepts of E factors and atom utilization for assessing the environmental impact of chemical processes.

Biocatalysis in ionic liquids

Asymmetric transformations catalyzed by enzymes in organic solvents

Enzymatic catalysis in monophasic organic solvents

Esterases (EC 3.1.1.x) represent a diverse group of hydrolases catalyzing the cleavage and formation of ester bonds and are widely distributed in animals, plants and microorganisms. Beside lipases, a considerable number of microbial carboxyl esterases have also been discovered and overexpressed. This review summarizes their properties and classification. Special emphasis is given on their application in organic synthesis for the resolution of racemates and prostereogenic compounds. In addition, recent results for altering their properties by directed evolution are presented.

http://envismadrasuniv.org/Microbes%20and%20Metals%20Interaction/pdf/Microbial%20carboxyl%20esterases.pdf

Gary Girdaukas

Papers

Quantitative analyses of biochemical kinetic resolutions of enantiomers

Quantitative analyses of biochemical kinetic resolution of enantiomers. 2. Enzyme-catalyzed esterifications in water-organic solvent biphasic systems

Bifunctional chiral synthons via biochemical methods. III. Optical purity enhancement in enzymic asymmetric catalysis

Dose- and Route-Dependent Teratogenicity, Toxicity, and Pharmacokinetic Profiles of the Hedgehog Signaling Antagonist Cyclopamine in the Mouse

Sequential biocatalytic kinetic resolutions