Alcohol dehydrogenase catalyzed

Alcohol dehydrogenase-catalyzed reduction of ketones is a convenient method for the production of chiral alcohols. HLAD, the most thoroughly studied enzyme, has a broad substrate specificity and accommodates a variety of substrates (Table 11). It efficiendy reduces all simple four- to nine-membered cycHc ketones and also symmetrical and racemic cis- and trans-decalindiones (167). Asymmetric reduction of aUphatic acycHc ketones (C-4—C-10) (103,104) can be efficiendy achieved by alcohol dehydrogenase isolated from Thermoanaerohium hrockii (TBADH) (168). The enzyme is remarkably stable at temperatures up to 85°C and exhibits high tolerance toward organic solvents. Alcohol dehydrogenases from horse Hver and T. hrockii... 

Table 11. Alcohol Dehydrogenase-Catalyzed Reductions on Ketones...

FIGURE 16.13 Liver alcohol dehydrogenase catalyzes the transfer of a hydride ion (H ) from NADH to acetaldehyde (CH3CHO), forming ethanol (CH3CH9OH). 

Future directions in alcohol dehydrogenase-catalyzed reactions... 

Alcohol dehydrogenases catalyze oxidation of alcohols in a reaction dependent on the pyridine nucleotide NAD+ [Eq. (5)]. Since the reaction is reversible, alcohol dehydrogenases also catalyze the reduction of aldehydes by... 

For further important work on this and related concepts, see Rucker, J. and Kliman, J.P. (1999). Computational study of tunneling and coupled motion in alcohol dehydrogenase-catalyzed reactions Implication for measured hydrogen and carbon isotope effects. J. Am. Chem. Soc. 121, 1997 -2006, and Kohen, A. and Jensen, J.H. (2002). Boundary conditions for the Swain-Schaad relationship as a criterion for hydrogen tunneling. J. Am. Chem. Soc. April 17, 124(15), 3858-3864. 

Reductions ofketones -alcohol dehydrogenase-catalyzed pNZYMES IN ORGANIC SYNTHESIS] (Vol 9)... 

Alcohol dehydrogenase-catalyzed reduction of ketones is a convenient method lor the production nf chiral alcohols. HI.AD, the most thoroughly studied enzyme, has a broad substrate specificity and accommodates a variety of substrates. 

W. Kruse, W. Hummel, and U. Kragl, Alcohol-dehydrogenase-catalyzed production of chiral hydrophobic alcohols. 

Alcohol Dehydrogenase. Alcohol dehydrogenases catalyze the conversion of alcohols to aldehydes or ketones ... 

KP Lok, TJ Jakovac, JB Jones. Enzymes in organic synthesis. 34. Preparation of enantiomerically pure exo- and endo-bridged bicyclic [2.2.1] chiral lactones via stereospecific horse liver alcohol dehydrogenase catalyzed oxidations of meso di-ols. J Am Chem Soc 107 2521-2526, 1985. 

The initial rates (v in juM/min) of liver alcohol dehydrogenase-catalyzed ethanal reduction are measured in the presence of pyrazole as an inhibitor at the constant concentration of NADH (0.02 M) and the constant concentration of ethanal (2.0 mM), respectively. Propose respective inhibition types and estimate their inhibition constants. 

Alcohol dehydrogenase catalyzes an oxidation the removal of two hydrogen atoms from the alcohol molecule. The oxidizing agent is nicotinamide adenine dinucleotide (NAD). NAD exists in two forms the oxidized form, called NAD+, and the reduced form, called NADH. The following equation shows that ethanol is oxidized to acetaldehyde, and NAD+ is reduced to NADH. 

Alcohol Dehydrogenase Catalyzed Synthesis of the Chiral Side... 

Irwin, A.J. and Jones, J.B. (1977) Regiospedfic and enantioselective horse liver alcohol dehydrogenase catalyzed oxidations of some hydroxycydopentanes. Journal of the American Chemical Society, 99, 1525-1530. 

By means of capillary gas chromatographic determination of the optical purities of formed products we could demonstrate that yeast alcohol dehydrogenase catalyzes not only the oxidation of racemic secondary alcohols but also the reduction of the corresponding methyl ketones in highly stereoselective manner. 

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