1999 Fiscal Year Final Research Report Summary
ELUCIDATION OF ANTIOXIDATIVE REACTION MECHANISM ON TREE PHENOLIC
| Project/Area Number |
09660177
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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 |
林産学
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| Research Institution | GIFU UNIVERSITY |
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Principal Investigator |
OHASHI Hideo GIFU UNIVERSITY, AGRICULTURE, PROFESSOR, 農学部, 教授 (80021723)
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| Project Period (FY) |
1997 – 1999
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| Keywords | tree phenolic constituent / flavonoid / flavonol / quercetin / antioxidative ability / radical-capturing / radical initiator / 1,1-diphenyl-2-picrylhydrazil (DPPH) |
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| Research Abstract |
We noticed on the antioxidative activity of wood phenolic constituents in order to develop the effective utilization of the extractives. On the present work, further characterization of flavonols on the antioxidative ability was undertaken.
At first, the revealing of radical-capturing reaction pathway which gegan at the C3 hydroxyl group of the flavonol was aimed. Before the main experiment, 5,7,3',4'-tetramethylquercetin (TMQ) was prepared from quercetin-3-0-β-rutinoside. TMQ representing flavonols was reacted with two radical initiators having strong and weak reactivities. The structures of isolated reaction products were elucidated, respectively. Also, the time course of these products were obtained. Based on both results, a possible reaction pathway having two blanched ways was presented. It was revealed that the reaction behavior of two subways was different between two radical initiators.
Nextly, comparison experiments of the radical-capturing ability against 1,1-diphenyl-2-picrylhydrazil (DPPH) by usual spectroscophic and stopped flow methods were carried out, using natural flavonoids such as chalcone, aurone, isoflavone, flavan-3-ols, and other compounds, together with flavonol constituents. From these results, the more advantage of flavonols was indicated. Furthermore, it was revealed that antioxidative constituents might be divided into two groups due to the reaction speed of radical-capturing.
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