1998 Fiscal Year Final Research Report Summary
Mechanism on Damage of the Purine Base in a Nucleic Acid Using the Electrogenerated Active Oxygen
| Project/Area Number |
09672192
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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 |
Physical pharmacy
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| Research Institution | Gifu Pharmaceutical University |
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Principal Investigator |
UNO Bunji Gifu Pharmaceutical University, Department of Pharmaceutical Science, Associate Professor, 薬学部, 助教授 (80160307)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Superoxide anion radical / Guanosine / Cyclic voltammetry / Hydroperoxy radical / Active oxygen / Spectroelectrochemistry / Molecular orbital calculation |
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| Research Abstract |
Active oxygens are generated in a body, coupled with derivation of the activated free radical from mutation substances. From the point of view considerable interest is devoted to mutation character of the active oxygens. In this work, I have investigated the mechanism on damage of the purine base in a nucleic acid in terms of interaction of the guanosine derivative with electrogenerated superoxide anion radical.
A reversible cyclic voltammogram of oxygen in DMF came out to be irreversible in the presence of guanosine. This arises from not a one-electron transfer mediated by superoxide anion radical but the EC mechanism. The reaction products are identified as guanine and its analog damaged in the purine base by the spectroelectrochemical and chromatographic measurements. A proton transfer from guanosine to electrogenerated superoxide anion radical leads to hydroperoxy radical. Generation of guanine is caused by hydrogen peroxide derived from the disproportionation reaction of hydroperoxy radical. It seems that guanosine reacts with hydroperoxy radical, yielding the product damaged in the purine base. Molecular orbital calculations partially support these conclusions. It has been found that the key reaction for the damage of the purine base in a nucleic acid is the proton transfer from guanosine to superoxide anion radical.
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