| Project/Area Number |
02804037
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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 |
有機化学一般
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| Research Institution | University of Tsukuba |
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Principal Investigator |
FUJIMORI Ken University of Tsukuba Department of Chemistry Associate Professor, 化学系, 助教授 (90015983)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Activation of Dioxygen / Superoxide Anion Radical / Oxide Anion Radical / Oxygen-18 Tracer / Hydrogen peroxide / Autoxidation / Determination of Superoxide / Hydroxyl Radical / ス-パ-オキサイド |
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| Research Abstract |
Molecular oxygen and hydroxide anion are the most fundamental row materials in oxygen chemistry. Inspection of redox potential of molecular oxygen and hydroxide anion suggest that these two species may react in aprotic solvent, in which naked hydroxide anion act as a single electron reducing agent.
When a solution of ^<18>O-fabelled cesium hydroxide in hexamethylphosphoric triamide was incubated with oxygen gas in sealed tube, incorporation of ^<18>O into molecular oxygen took place even at room temperature. Since oxide anion radical were known to mediate oxygen scrambling between hydroxide anion and molecular oxygen, the our observation has been rationalyzed as follows. The single elctron transfer from hydroxide anion to molecular oxygen forming superoxide anion radical(O_<2->)and oxide anion radical(O^-)which is the conjugate base of hydroxyl radical(HO). Then the ^<18>O-D1labelled oxide anion radical reacts with unlabelled molecular oxygen to form ozone anion radical(O_<3->)which collapsed to afford unlabelled oxide anion radical and ^<18>O-labelled molecular oxygen.
We found that hydroperoxyl radical, the conjugate acid of superoxide anion radical, Initiates autoxidation of dihydronfootinamide adenine dinucleotide phosphate(NADPH). We have established the method measuring steady state concentration of superoxide anion radical based on the rate of hydroperoxyl radical dependent autoxidation of NADPH. The method was applied successfully to determine steady state concentration of superoxide anlon radical in some biochemical processes.
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