2004 Fiscal Year Final Research Report Summary
Development of Biocatalysts Using Organized Nano-reactors
| Project/Area Number |
15550093
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
EMA Tadashi OKAYAMA UNIVERSITY, Faculty of Engineering, Associate Professor, 工学部, 助教授 (20263626)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Takashi OKAYAMA UNIVERSITY, Faculty of Engineering, Professor, 工学部, 教授 (00170556)
KORENAGA Toshinobu OKAYAMA UNIVERSITY, Faculty of Engineering, Assistant Professor, 工学部, 助手 (70335579)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Biocatalyst / Enzyme / Lipase / Immobilization / High temperature / Enantioselectivity / Kinetic resolution / Asymmetric reduction |
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| Research Abstract |
Kinetic resolution of 1,1-diphenyl-2-propanol was performed at high temperatures using a lipase immobilized on porous ceramics, Toyonite 200M. Reactions proceeded even at 120℃, giving enantiomerically pure ester product. In contrast, the reaction at 100℃ using the same lipase immobilized on Celite resulted in no reaction. The high-temperature biocatalysis in supercritical CO_2 medium at 80℃ gave 42% conversion with an E value of 211. The lipase-catalyzed acylation of a secondary alcohol having tetraphenylporphyrin as a substituent proceeded at 60℃ most efficiently, giving enantiomerically pure ester and alcohol.
Lipase mutant was immobilized on the porous ceramics to study how far the enantioselectivity can be controlled on the basis of a reaction mechanism. Substitution of some amino acid residue in the proximity of the active site with another one resulted in a change in enantioselectivity, as expected. Thermodynamic parameters suggested that the change in enantioselectivity was driven by the change in activation enthalpy.
A new method for the prediction of absolute configurations of secondary alcohols using immobilized lipase was invented. Using the E values for two kinds of 1-substituted ethanols having different substituents, the E value for another secondary alcohol having the two substituents on both sides was predicted and determined. The experimental results for 19 out of 20 examples were consistent with the prediction.
A carbonyl reductase obtained with recombinant E.coli was immobilized on the porous ceramics, which unfortunately showed no remarkable effect. Rather, whole-cell reductions using E.coli coexpressing two genes encoding the carbonyl reductase and a glucose dehydrogenase gave optically active alcohols much more easily and efficiently. Highly enantioselective asymmetric reductions were achieved, and 8 out of 16 ketones were reduced to optically active alcohols with >98% ee.
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Research Products
(6 results)
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[Journal Article] Lipase-Catalyzed Resolution of (2R^*,3S^*)- and (2R^*,3R^*)-3-Methyl-3-phenyl-2-aziridinemethanol at Low Temperatures and Determination of the Absolute Configurations of the Four Stere oisomers.2005
Author(s)
Sakai, T., Liu, Y., Ohta, H., Korenaga, T., Ema, T.
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Journal Title
The Journal of Organic Chemistry 70
Pages: 1369-1375
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Asymmetric Reduction of a Variety of Ketones with a Recombinant Carbonyl Reductase : Identification of the Gene Encoding a Versatile Biocatalyst.2005
Author(s)
Ema, T., Yagasaki, H., Okita, N., Nishikawa, K., Korenaga, T., Sakai, T.
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Journal Title
Tetrahedron : Asymmetry 16
Pages: 1075-1078
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Lipase-Catalyzed Resolution of (2R^*,3S^*)-and (2R^*,3R^*)-3-Methyl-3-phenyl-2-aziridinemethanol at Low Temperatures and Determination of the Absolute Configurations of the Four Stereoisomers.2005
Author(s)
Sakai, T., Liu, Y., Ohta, H., Korenaga, T., Ema, T.
-
Journal Title
The Journal of Organic Chemistry 70
Pages: 1369-1375
Description
「研究成果報告書概要(欧文)」より
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