1988 Fiscal Year Final Research Report Summary
Enzymatic processes for the production of D-pantoyl lactone and related optically active hydroxylated compounds
| Project/Area Number |
62560102
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
発酵・醸造
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| Research Institution | Kyoto University |
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Principal Investigator |
SHIMIZU Sakayu Kyoto University, 農学部, 助手 (70093250)
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| Co-Investigator(Kenkyū-buntansha) |
NAGASAWA Toru Kyoto University, 農学部, 助手 (60115904)
IZUMI Yoshikazu Kyoto University, 農学部, 助教授 (40026555)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Stereoselective reaction / D(-)-pantoyl lactone / Nocardia asteroids / Candida parapsilosis / Candida parapsilosis / Rhodotorula minuta / Nocardia asteroides |
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| Research Abstract |
The efficient enzymatic conversion of ketopantoyl lactone to D-(-)-pantoyl lactone was found to take place on incubation with washed cells of Candida parapsilosis IFO 0708 or Rhodotorula minuta IFO 0920. They showed high conversion activity when grown with 5% corn steep liquor and 5% glucose, sucrose,maltose or glycerol.Under suitable reaction conditions the amounts of D-(-)-pantoyl lactone reached 49.5g/l(94.4%e.e; molar yield,99%) and 89.9g/l(80.4%e.e; molar yield,99%)with cells of R.minuta and C.parapsilosis,respectively.
A novel enzymatic process for the synthesis of D(-)-pantoyl lactone from a racemic mixture of pantoyllactone was also developed.The process involves the stereospecific oxidation of the L(+)-isomer of pantoyl lactoneto ketopantoyl lactone followed by its asymmetric reduction to the D(-)-isomer. The oxidation is carried out with cells of Nocardia asteroides AKU 2103 as the catalyst, which convert only the L(+)-isomer of pantoyl lactone to keto-pantoyl lactone without any modification of the remaining D(-)-isomer.With 80gl^<-1> DL-pantoyl lactone as the substrate,>90%of the added L(+)-isomer was converted to ketopantoyl lactone under the optimum reaction conditions. The ketopantoyl lactone that accumulated in the reaction mixture was almost specifically converted to the D(-)-isomer of pantoyl lactone on incubation with cells of Candida parapsilosis IFO 0784. Scince this process is simple and requires no reracemization step, which is necessary for conventional chemical resolution, it is highly advantageous for the practical synthesis of D(-)-pantoyl lactone.
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