| Project/Area Number |
09660118
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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 |
Bioproduction chemistry/Bioorganic chemistry
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| Research Institution | Tottori University |
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Principal Investigator |
NAKAJIMA Hiromitsu Tottori University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (40144646)
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| Co-Investigator(Kenkyū-buntansha) |
HAMASAKI Takashi Tottori University, Faculty of Agriculture, Professor, 農学部, 教授 (40032081)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | plant pathogens / phytotoxins / biosynthesis / Bipolaris sorokiniana / sesquiterpene / L- [hydroxy-^<18>O] malic acid / sorokinianin |
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| Research Abstract |
Sorokinianin is a phytotoxin produced by a strain (OB-25-l) of Bipolaris sorokiniana, a pathogen causing spot blotch or foot and root rot diseases of wheat and other grasses. This toxin is assumed to be composed of a helminthosporol-type sesquiterpene and a C_3 portion. To clarify the biosynthetic origin we conducted three experiments : a [1,2-^<13>C_2] sodium acetate feeding experiment ; a replacement culture experiment with the candidates for the C_3 unit precursor, together with prehelminthosporol, the major metabolite of the strain OB-25-1 ; and a [2,3-^<13>C_2] succinic acid feeding experiment. The results of these experiments suggested that sorokinianin was synthesized from prehelminthosporol by reactions that include the addition of a member of the TCA cycle, decarboxylation and lactonization. To determine the direct C_3 unit precursor we prepared L-[hydroxy-^<18>O] malic acid from fumaric acid by fumarase and H_2_<18>O and conducted a L-[hydroxy-^<18>O] malic acid feeding experiment. The results of the experiment indicated that the direct C_3 unit precursor was not malic acid/oxalacetic acid but fumaric acid/succinic acid.
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