Baker’s yeast alcohol dehydrogenases

Different purified or partially purified enzymes were tested successfully, such as horse liver dehydrogenase [3], Sulfolobus solfataricus dehydrogenase [4], Pischia pastoris alcohol oxidase [5, 6], the baker s yeast alcohol dehydrogenase [7], and finally lipolytic enzymes, which probably constitute the major part of the work devoted to the use of enzymes working at the solid/gas interface, as summarized in a recent publication [8]. 

Yang, R and Russell, A. 1., Optimization of baker s yeast alcohol dehydrogenase activity in an organic solvent, BiotechnoL Prog., 9, 234—241, 1993. 

In 1994, a two-step conversion of an ester to an aldehyde was performed in reverse micelles formed with a variety of surfactants by using a combination of lipase and baker s yeast alcohol dehydrogenase [148]. The activity of the two enzymes was affected by the natnre of the snrfactants and the water content of the reverse micellar system. The aldehyde prodnced from the reaction partitions in the organic solvent thns preventing the enzyme s inhibition which is normally observed in aqueous solution. 

The two oxidoreductase systems most frequentiy used for preparation of chiral synthons include baker s yeast and horse hver alcohol dehydrogenase (HLAD). The use of baker s yeast has been recendy reviewed in great detail (6,163) and therefore will not be coveted here. The emphasis here is on dehydrogenase-catalyzed oxidation and reduction of alcohols, ketones, and keto acid, oxidations at unsaturated carbon, and Bayer-Vidiger oxidations. 

Alcohol dehydrogenase Baker s yeast 7.5 24 4 1 Morild (1977a)... 

Finally, (S )-coriolic acid (a metabolite of hnoleic acid) has been synthesized, in an enan-tiospecific fashion, by the use of the alcohol dehydrogenase enzyme from baker s yeast in the presence of NADPH. In the key step of this synthesis, the supported enzyme/NADPH was used to reduce a bromovinyl ketone enantiospecifically (equation 71)291. 

Chiral alcohols are valuable products mainly as building blocks for pharmaceuticals or agro chemicals or as part of chiral catalysts. Cheap biotransformation methods for the selective reduction of particular ketone compounds are known for many years rather catalyzed by fermentation than with isolated enzymes. Products prepared with whole cells such as baker s yeast often lack high enantioselectivity and there were several attemps to use isolated enzymes. Resolution of racemates with hydrolases are known in some cases but very often the reduction of the prochiral ketone using alcohol dehydrogenases are much more attractive. 

Alcohol dehydrogenase (ADH) from baker s yeast (Saccharomvces cerevi-siae) is a major enzyme involved in the oxidation of secondary alcohols and the reduction of methyl ketones, respectively. The stereochemical course of the oxidation has been investigated using racemic butan-2-ol and octan-2-ol as substrates only the (S)-enantiomers of these alcohols were converted to the corresponding ketones 22,2i). 

The following enzymes and coenzymes are abbreviated HLADH, horse liver alcohol dehydrogenase YADH, yeast alcohol dehydrogenase PTADH, Pseudomonas testosteronii alcohol dehydrogenase NAD(P) and NAD(P)H, oxidized and reduced forms of nicotinamide adenine diphosphate (or its phosphate) respectively BY, baker s yeast TBADH, Thermoanaerohium hrockii alcohol dehydrogenase ... 

In addition to stereoselective metalation, other methods have been applied for the synthesis of enantiomerically pure planar chiral compounds. Many racemic planar chiral amines and acids can be resolved by both classical and chromatographic techniques (see Sect. 4.3.1.1 for references on resolution procedures). Some enzymes have the remarkable ability to differentiate planar chiral compounds. For example, horse liver alcohol dehydrogenase (HLADH) catalyzes the oxidation of achiral ferrocene-1,2-dimethanol by NAD to (S)-2-hydroxymethyl-ferrocenealdehyde with 86% ee (Fig. 4-2la) and the reduction of ferrocene-1,2-dialdehyde by NADH to (I )-2-hydroxymethyl-ferrocenealdehyde with 94% ee (Fig. 4-2lb) [14]. Fermenting baker s yeast also reduces ferrocene-1,2-dialdehyde to (I )-2-hydroxymethyl-ferro-cenealdehyde [17]. HLADH has been used for a kinetic resolution of 2-methyl-ferrocenemethanol, giving 64% ee in the product, (S)-2-methyl-ferrocenealdehyde... 

The use of oxidoreductases in solution clearly dominates over immobilized applications. Use of immobilized whole cells (e.g. baker s yeast) [16] is, however, well described, and reports have also appeared claiming increased stability and activity of isolated horse liver alcohol dehydrogenase and other oxidoreductases immobilized on agarose [17] or salt crystals [18] (protein-coated microcrystals, PCMC [19]). Furthermore, immobilization of oxidoreductases on surfaces has been studied more intensively for the development of biosensors. 

Racemic formyl[4]ferrocenophanc is selectively reduced by baker s yeast with 80-89% ee but the yield is low (20%)306. Tricarbonyl(l-formyl-2-methylcyclopentadienyl)manganese is selectively reduced by horse liver alcohol dehydrogenase and two yeast strains which are also able to reduce the corresponding 1-acetyl compound307. 

Pentacyclo[5.4.0.02 6.0310.05 9]undecane-8,ll-dione is reduced cither by baker s yeast or by horse liver alcohol dehydrogenase, but the enantiosclcctivity is only moderate (50-72%... 

Willoughby N.A., Kirschner T., Smith M.P., Hjorth R. and Titchener-Hooker N.J. 1999. Immobilised metal ion affinity chromatography purification of alcohol dehydrogenase from baker s yeast using an expanded bed adsorption system, J. Chromatogr. A, 40, 195-204. 

A chemo-enzymatic enantiospecific synthesis of (S)-coriolic acid, (13S)-hy-droxy-18 2(9Z,ll ), mediated via immobilized alcohol dehydrogenase of baker s yeast has been described (31). 15,16-Didehydrocoriolic acid, 13-hydroxy-18 3(9Z, 11E, 15Z), was stereoselectively synthesized starting from pent-2-en-4-yn-1 -ol (32). Four stereoisomers of 9,10,13-trihydroxy-18 l(ll ) were derived from methyl 9,10-epoxy-12-octadecenoate. The latter was obtained by partial epoxidation of methyl linoleate. These trihydroxy C j g fatty acids are potential antirice blast fungal substances (33). (115)-Hydroxy-(125,13S)-epoxy-18 2(9Z,15Z) was synthesized from D-mannose (34). 

Bhalerao, U.T., L. Dasaradhi, C. Muralikrishna, and N.W. Fadnavis, A Novel Chemoen-zymatic Enantiospecific Synthesis of (5)-Coriolic Acid Mediated Via Immobilized Alcohol Dehydrogenase of Baker s Yeast, Tetrahedron Lett. 34 2359-2360 (1993). 

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