Microbial oxidation of alcohols

Microbial Oxidation of Alcohols by Candida boidinii Selective Oxidation... 

NOZAKIET AL. Microbial Oxidation of Alcohols fry Candida boidinii 195... 

Gestodene has been prepared in several ways (85). The route that provides the highest yield is shown in Eigure 8. Microbial oxidation of (55) with Penicillium raistrickii results in the 15-alcohol (56). Protection of the alcohol as the acetate (57) and protection of the ketone as a dienolether provides (58). In a one-pot procedure (58) is treated with lithium acetyUde and subjected to a hydrolytic work-up to provide gestodene (54) (86). 

Oxidation of secondary or primary alcohols by dehydrogenases is usually not performed biocatalytically. The reaction destroys a stereocentre, it is thermodynamically not favoured and product inhibition is a problem. It is attractive only in cases where it is necessary to discern between several hydroxy groups in a molecule. Microbial oxidation of D-glucitol to yield L-sorbose is the key step in production of vitamin C (Reichstein and Griissner, 1934). 

Subterminal alkane oxidation apparently occurs in some bacterial species (Markovetz, 1971). This type of oxidation is probably responsible for the formation of long-chain secondary alcohols and ketones. Pirnik (1977) and Perry (1984) have reviewed the microbial oxidation of branched and cyclic alkanes, respectively. Interestingly, none of the cyclohexane or cyclopentane compounds seems to be metabolized by pure cultures. Rather, non-specific oxidases present in many bacteria convert the cyclic alkanes into cyclic ketones, which are then oxidized by specific bacteria. 

The role of PQQ as cofactor has been established unequivocally only for a number of dehydrogenases that are located in the periplasmic space of gram-negative bacteria [3] (Table 1). These enzymes are involved in the oxidation of alcohols and sugars (to aldehydes and sugar lactones or ketosugars, respectively), especially in processes known as incomplete microbial oxidations [47] (production... 

Microbial oxidation of alkanes can take place at the terminal carbon, in which case an alcohol is the initial product, or at a subterminal position (often the -position) to give either the secondary alcohol or a ketone. In both cases further oxidation s can take place to give carboxylic acids, themselves liable to oxidation and shortening of the carbon chain by successive two-carbon units (Scheme 2). 

Acyclic tritetpenes can be considered as aliphatic hydrocarbons and are a iydroxylated by a numbo of microorganisms. The microbial oxidation of a varied of acyclic terpenoid hydrocarbons has been investigated by Nakajima, and aldrough terminal alcohols can obtained, for example pristanol (39) from pristane (38 equation 11), further oxidation can also occur. 

Anthony, C., and Zatman, L. J., 1967, The microbial oxidation of methanol The prosthetic group of alcohol dehydrogenase of Pseudomonas sp. M27 A new oxidoreductase prosthetic group. Biochem. J. 104 9609969. 

Oxidation of Meso Diols. Asymmetric induction of meso and prochiral diols by lipases is very successful in the field of organic synthesis. Also it is well known that selective oxidation of prochiral or meso diols by HLADH provides oxidized products with a significant degree of enantioselectivity. However, it has not been reported that alcohol oxidases were applied to such types of oxidation. The microbial oxidation of meso diols by Candida boidinii SA051 was carried out and gave optically active hydroxy ketones (Figure 8). 

In Banwell s de novo synthesis of Neu5Ac [136] cis-1,2-dihydrocatechol 228, a product of microbial oxidation of chlorobenzene, has been converted into a protected form of Neu5Ac via a fifteen steps reaction sequence (Scheme 50). Synthesis started from azido alcohol 229, obtained from catechol 228 by an established procedure [137]. This was subjected to ozonolytic cleavage and a reductive work-up to afford diol 230. Protection-deprotection reaction sequence led to alcohol 232 which was then oxidized to D-mannosamine derivative 233 using the Swem protocol. Condensation with the organozinc reagent derived from... 

At lower pH values (<4-5) acetic acid inhibits the growth of bacteria, yeasts and to a lesser extent the growth of moulds. The inhibitory effect is greater than due to pH alone. One assumes that undissociated acetic acid because of its good lipid solubility can penetrate the microbial cell and exert its antimicrobial effect. Bacteria of the genus Acetobacter can produce acetic acid by the oxidation of alcohol. In combination with heat acetic acid is especially effective. 

More recently, it has been discovered that a ds-dihydrocatechol derivative of cydohexadiene, conveniently produced from the microbial oxidation of benzene, can be converted to a variety of derivatives and polymoized using radical initiators. These polymers can be converted to PFP therm y at much Iowa temperatures, eliminating alcohols or acetic add (Tconv 250-300 C for R = Me, figure 31). The concern over 1,2-linkages in the polymer persists with these precursors. However, they have provided a low temperature route to high molecular weight PH. ... 

Microbial transformations, and yeast-mediated conversions in particular, have been widely used since the early days of mankind for the production of dairy products, bread, and alcoholic beverages. Whereas all of these early applications used mixed cultures of microorganisms it was the merit of Pasteur in 1862 [1] to lay a scientific foundation of one of these early applications, namely, the oxidation of alcohol to acetic acid by using a pure culture of Bacterium xylinium. All of these early biotechnological operations have been more or less directed in the areas of agricultural and humane nutrition the reduction of furfural to furfuryl alcohol under anaerobic conditions of fermentation, however, by means of living yeast [2,3] was the first phytochemical reduction of an organic molecule described in the literature. 

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