Enzymes in Nonaqueous Solvents

Enzymatic catalysis has gained considerable attention in recent years as an efficient tool in the preparation of natural products, pharmaceuticals, fine chemicals, and food ingredients. The high selectivity and mild reaction con- tions associated with enzymatic transformations have made this approach an attractive alternative in the synthesis of complex bioactive compounds, which are often difficult to obtain by standard chemical routes. However, the maj- ity of organic compounds are not very soluble in water, which was traditi- ally perceived as the only suitable reaction medium for the application of biocatalysts. The realization that most enzymes can function perfectly well under nearly anhydrous conditions and, in addition, display a number of useful properties, e. g. , highly enhanced stability and different selectivity, has d- matically widened the scope of their application to the organic synthesis. Another great attraction of using organic solvents rather than water as a reaction solvent is the ability to perform synthetic transformations with re- tively inexpensive hydrolytic enzymes. It is worth reminding the reader that in vivo, the synthetic and hydrolytic pathways are catalyzed by different enzymes. However, elimination of water from the reaction mixture enables the reversal of hydrolytic enzymes and thus avoids the use of the expensive cofactors or activated substrates that are required for their synthetic count- parts.

Includes supplementary material: sn.pub/extras

Klappentext
In recent years, enzymatic catalysis in organic solvents-as opposed to aqueous solutions-has gained considerable attention as a powerful new approach to the preparation of natural products, pharmaceuticals, fine chemicals, and food ingredients. In Enzymes in Nonaqueous Solvents: Methods and Protocols, leading chemists, biochemists, biotechnologists, and process engineers summarize for the first time a wide range of methods for executing enzymatic transformations under nonaqueous conditions. Each method includes detailed step-by-step instructions for its successful completion, a list of materials, and ancillary notes that explain the scientific basis of the procedure, as well as troubleshooting. Also provided are a generic description of key reactions, advice on biocatalyst preparation, discussion of reaction conditions, and instructions on bioreactor design.
Comprehensive and state-of-the-art, Enzymes in Nonaqueous Solvents: Methods and Protocols offers today's synthetic chemists, biochemists, and process engineers all the essential information needed to carry out enzymatic reactions in nonaqueous media, as well as to successfully scale up to production quantities.

Inhalt
Control of Enzyme Activity in Nonaqueous Solvents.- Salt-Induced Activation of Enzymes in Organic Solvents.- Imprinting Enzymes for Use in Organic Media.- Entrapment of Biocatalysts by Prepolymer Methods.- Microencapsulation of Enzymes and Cells for Nonaqueous Biotransformations.- Immobilization of Lipases on Hydrogels.- Polyethylene Glycol-Modified Enzymes in Hydrophobic Media.- Chemical Modification of Lipase for Use in Ester Synthesis.- Preparation and Properties in Organic Solvents of Noncovalent PEG-Enzyme Complexes.- Preparation of a Lipid-Coated Enzyme and Activity for Reverse Hydrolysis Reactions in Homogeneous Organic Media.- Very High Activity Biocatalysts for Low-Water Systems.- Methods for Measurement and Control of Water in Nonaqueous Biocatalysis.- Water Activity Control in Organic Media by Equilibration Through Membranes.- Water Activity Control for Lipase-Catalyzed Reactions in Nonaqueous Media.- Immobilization of Enzymes and Control of Water Activity in Low-Water Media.- Enzyme Activity and Enantioselectivity Measurements in Organic Media.- Calorimetric Methods in Evaluating Hydration and Solvation of Solid Proteins Immersed in Organic Solvents.- Detection of Structural Changes of Enzymes in Nonaqueous Media by Fluorescence and CD Spectroscopy.- The Effects of Crown Ethers on the Activity of Enzymes in Organic Solvents.- Control of Acid-Base Conditions in Low-Water Media.- Enzymatic Acylation of ?-Butylglucoside in Nonaqueous Media.- Synthetic Applications.- Choosing Hydrolases for Enantioselective Reactions Involving Alcohols Using Empirical Rules.- Candida antarctica Lipase B A Tool for the Preparation of Optically Active Alcohols.- Enantioselective Lipase-Catalyzed Transesterifications in Organic Solvents.- Pseudomonas cepacia Lipase-CatalyzedEnantioselective Acylation of 2-Substituted-1-alkanols in Organic Solvents.- Preparation of 2-, 3-, and 4-Methylcarboxylic Acids and the Corresponding Alcohols of High Enantiopurity by Lipase-Catalyzed Esterification.- Optimization of Enzymatic Enantiomeric Resolutions Through Solvent Selection.- Chemoselective Amidification of Amino-Polyols Catalyzed with Lipases in Organic Solvents.- Synthesis of Esters Catalyzed by Lipases in Water-in-Oil Microemulsions.- Enzymatic Conversion of Organosilicon Compounds in Organic Solvents.- Synthetic Applications of Enzymes in Nonaqueous Media.- Enzymes in Nonaqueous Solvents.- Interface Bioreactor.- Yeast-Mediated Reactions in Organic Solvents.- Biocatalysis in Pharmaceutical Process Development SCH56592, A Case Study.- Reaction Systems and Bioreactor Design.- Enzymatic Solid-to-Solid Peptide Synthesis.- Enzymatic Synthesis and Hydrolysis Reactions of Acylglycerols in Solvent-Free Systems.- Solid-Gas Catalysis at Controlled Water Activity.- Solvent-Free Biotransformations of Lipids.- Lipase-Catalyzed Synthesis of Sugar Fatty Acid Esters in Supercritical Carbon Dioxide.- Transformations in Frozen Aqueous Solutions Catalyzed by Hydrolytic Enzymes.- Enzymatic Synthesis of Sugar Fatty Acid Esters in Solvent-Free Media.- Biotransformations in Supersaturated Solutions.- Enzymatic Transformations in Suspensions (I) One Solid Substrate and Product.- Biotransformations in Supercritical Fluids.- Reverse Micellar Systems.- Enzymatic Transformations in Supercritical Fluids.- Enzymatic Transformations in Suspensions (II).- Characterization and Operation of a Micellar Membrane Bioreactor.- Immobilization of Lipase Enzymes and Their Application in the Interesterification of Oils and Fats.