1996 Fiscal Year Final Research Report Summary
Biocatalytic Asymmetric Redcution of Ketones in an Organic Solvent.
| Project/Area Number |
06453063
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物質変換
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NAKAMURA Kaoru Kyoto University・Institute for Cheimcal Research, Associate Professor, 化学研究所, 助教授 (10101239)
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| Project Period (FY) |
1994 – 1996
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| Keywords | ASYMMETRIC SYNTHESIS / BIOCATALYSIS / MICROBE / ENZYME / ORGANIC SOLVENT / REDUCTION / IMMOBILIZE / LIPASE |
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| Research Abstract |
Effect of an organic solvent on biocatalytic asymmetric reduction has been investigated. We have found the following three novel results.
1) Yeast reduction of alpha-keto esters proceeds smoothly in benzene when dry bakers'yeast was used and the yeast was finely powdered. The yeast reduction in benzene afforded the different stereoselectivity from that in aqueous solution. Thus, (R) -hydroxy esters were obtained by the reaction in benzene while the antipodes were afforded by the reaction in an aqueous solution. We have isolated the enzymes which reduce alpha-keto esters and have elucidated the mechanism of the stereochemical control by using an organic solvent in microbial reduction.
2) The low enantioselectivity in the reduction of acetophenone by a fungus, Geotrichum candidum, was increased up to over 99% ee by using an immobilized microbe in an organic solvent with the aid of a reductant such as 2-alkanol. Other aromatic ketones were also reduced to the corresponding (S) -alcohols by the same method.
3) Effect of solvents on enantioselectivity of a lipase has been investigated and found that the selectivity depends upon the polarity and shape of the organic solvent used in the reaction.
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