Stereochemical control of microbial reduction. 17. A method for controlling the enantioselectivity of reductions with bakers' yeast

Asymmetric Reduction of Heteroaryl Methyl Ketones Using <i>Daucus carota</i>

“…The present process developed has the advantage over the currently known chemical and biological methodologies in obtaining value added chiral aromatic hetero alcohols in higher yields and enantioselectivity [28,29]. To study the steric-orientation of the enzyme active site in enantioselective reduction of the heteroaryl methyl ketones to respective chiral alcohols, it is planned to carry out chemical additive studies like allyl bromide and ethylenediamine tetra acetic acid (EDTA) that influence the stereoselectity in enzymatic bioreduction processes [30][31][32]. On addition of allyl bromide (0.2 mM solution) to the incubation medium the process of bio-reduction of pyridyl ketones to chiral alcohols using D.carota, was found increased by 20% -40%, whereas no difference was observed in the enzyme dehydrogenase activity on addition of EDTA (0.5 mM) (results not presented).…”

Stereoselective Reduction of Carbonyl Compounds Using the Cell-Free Extract of the Earthworm,Lumbricus rubellus, as a Novel Source of Biocatalyst

“…For example, bakers' yeast (Saccharomyces cerevisiae) has often been used for the reduction of keto esters to obtain optically active hydroxyl esters. 4,5) Furthermore, other microorganisms (such as yeast, 6) aerobic bacteria, [7][8][9] and microalgae 10) ) or plant cultured cells 3) that can catalyze the stereoselective reduction of keto esters are also used for the preparation of chiral hydroxyl esters. As described above, the biotransformation using microorganisms or plant cells as biocatalysts has been widely investigated, however, the bioconversion using other organisms, such as invertebrates, has rarely been reported.…”

Purification and Characterization of Two α-Keto Ester Reductases fromStreptomyces thermocyaneoviolaceusIFO 14271

“…[7][8][9] Furthermore, several yeast keto ester reductases (YKERs) were isolated from bakers' yeast and their enzymatic properties studied including the speciˆc activity, stereoselectivity, and kinetic parameters. [10][11][12][13][14] Other microorganisms such as Thermoanaerobactor brockii, 15) Geotrichum candidum, 16,17) and Klebsiella pneumoniae 18) that can also catalyze the asymmetric reduction of keto esters are also used for the preparation of chiral hydroxy esters. However, little information is known from mechanistic studies of enzymatic reduction by their microorganisms.…”