Saccharomyces cerevisiae keto esters

Padhi, S.K., Kaluzna, I.A., Buisson, D. et al. (2007) Reductions of cyclic beta-keto esters by individual Saccharomyces cerevisiae dehydrogenases and a chemo-enzymatic route to (lR,2S)-2-methyl-l-cyclohexanol. Tetrahedron Asymmetry, 18 (18), 2133-2138. 

Metal amalgams may be used for reduction of the keto groups in keto esters provided the medium does not cause hydrolysis of the ester. Because of that aluminum amalgam in ether is preferable to sodium amalgam in aqueous solutions. Diethyl oxalacetate was reduced to diethyl malate by sodium amalgam in 50% yield and with aluminum amalgam in 80% yield [148], Stereospecific reduction of a- and fi-keto esters to optically pure hydroxy esters was achieved by biochemical reduction in moderate to good yields. Saccharomyces cerevisiae converted methyl 2-keto-2-phenylacetate to methyl... 

Saccharomyces cerevisiae (freeze-dried) TL 34 3949 (1993) (0-keto ester)... 

Optically pure a- and j8-hydroxy esters and amides have been produced from the corresponding keto-deiivatives by reduction with the yeast Saccharomyces cerevisiae yields are good in many cases but overall conversions are often low. 

Nakamura et al. [77] isolated four different oxidoreductase from baker s yeast, which catalyzed the reduction of P-keto esters to p-hydroxy esters. Two oxidoreductases, namely, D-enzyme 1 (mw 25,000) and D-enzyme 2 (mw 1,600,000) catalyzed the reduction of p-keto ester stereoselectivity to d-p-hydroxy ester. In contrast, one other enzyme, L-enzyme (mw 321,000) reduced substrates to L-p-hydroxy esters. The NADP-oxidoreduc-tases, designated the 5 and R enzymes, have been purified and characterized from cell extracts of Saccharomyces cerevisiae, which catalyze the enantioselective reductions of 3-... 

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