| Project/Area Number |
11672222
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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 |
医薬分子機能学
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| Research Institution | National Institute of Radiological Sciences |
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Principal Investigator |
IKOTA Nobuo National Institute of Radiological Sciences, 1st Research group, subgroup leader, 第一研究グループ, サブグループリーダー (80159649)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAGAWA Hidehiko National Institute of Radiological Sciences, 1st Research group, senior researcher, 第一研究グループ, 主任研究員 (80281674)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | reactive oxygen species / reactive nitrogen species / peroxynitrite / superoxide / hydroxyl radical / nitrotyrosine / spintrapping method / polyphenol / 抗酸化剤 / フラボノイド / ジチロシン |
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| Research Abstract |
Explorative study on scavenger for superoxide and hydroxyl radical, as reactive oxygen species, and peroxynitrite as reactive nitrogen species from natural producs and synthetic compounds was conducted. The scavenging abilities were estimated with ESR spin-trapping method using DMPO as spin trapping reagent for superoxide and hydroxyl radical, and with HPLC for peroxynitrite. Nitrating and oxidizing activities were estimated by the formation of 3-nitrotyrosine and dityrosine with a HPLC-UV-fluorescence detector system. The compounds used in this study were chalcon, 5-methoxytryptaminyl caffeic acid amide, extract from apple, RK-160 and RK-02B(extract from licorice), and trolox(synthetic aqueous soluble vitamin E derivative). Superoxide was generated from hypoxantine-xantine oxidase system and hydroxyl radical was generated from Cu(en)_2-H_2O_2 system. Peroxynitrite was prepared from ozone and sodium azide. Chalcon, extract from apple, and RK02B showed high scanenging ability against superoxide, hydroxyl radical, and peroxynitrite.
During the study on scavenger for peroxynitrite, we have found that 5-methoxytryptamine and a-lipoic acid only inhibited the nitration reaction, and enhanced the formation of an oxidation product. This is important evidence that there are different intermediates in the nitrating and oxidizing reactions of L-tyrosine by peroxynitrite such as caged dipolar form [ONO^+ ……^-ON].
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