Spin-Trapping Study on the Hydroxyl Radical Formed from a Tea Catechin-Cu(II) System.

• YOSHIOKA Hisashi

  Institute for Environmental Sciences, University of Shizuoka

• SENBA Yasushi

  Institute for Environmental Sciences, University of Shizuoka

• SAITO Kieko

  Institute for Environmental Sciences, University of Shizuoka

• KIMURA Takahide

  Department of Chemistry, Shiga University of Medical Science

• HAYAKAWA Fumiko

  Department of Life Style Studies, School of Human Cultures, The University of Shiga Prefecture

書誌事項

タイトル別名

• Spin Trapping Study on the Hydroxyl Radical Formed from a Tea Catechin Cu 2 System

抄録

A spin-trapping method was applied to examine the formation of the hydroxyl (OH) radical from a tea catechin-Cu(II) system to elucidate a previous result that some tea catechin-Cu(II) systems induced DNA scission. Three tea catechins, (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCg) and (−)-epicatechin (EC), were used. The spin-trapping agent, 5,5'-dimethyl-pyrroline-1-oxide (DMPO), was dissolved in a pH 9 phosphate buffer solution, then a catechin and Cu(II) were added in that order, and the ESR spectral change was monitored for one hour. The order of adding the catechin and Cu(II) was then reversed, and the ESR spectral change was again monitored to examine the coordinating activity of each catechin toward the Cu(II) ion and the effect on OH radical generation. The intensity changes of the spin adducts, DMPO-OH, DMPO-CH3 and DMPO-H, were analyzed, the results suggesting that the OH radical generated in the system decomposed DMPO, resulting in the formation of DMPO-CH3 and DMPO-H. The results show that EGC formed a stable complex with Cu(II) and generated the OH radical. EGCg seemed to have this activity, but the OH radical that was generated was scavenged by the gallate group existing in the complex. EC did not show strong coordinating and OH-generating activities. These characteristics of the three catechins are consistent with the results shown for DNA scission.

収録刊行物

• Ｂｉｏｓｃｉｅｎｃｅ，　Ｂｉｏｔｅｃｈｎｏｌｏｇｙ，　ａｎｄ　Ｂｉｏｃｈｅｍｉｓｔｒｙ

  Ｂｉｏｓｃｉｅｎｃｅ，　Ｂｉｏｔｅｃｈｎｏｌｏｇｙ，　ａｎｄ　Ｂｉｏｃｈｅｍｉｓｔｒｙ 65 (8), 1697-1706, 2001

  公益社団法人 日本農芸化学会

キーワード

• spin trapping method
• hydroxyl radical
• 5,5'-Dimethyl-1-pyrroline N-oxide (DMPO)
• tea catechin
• cupric ion

詳細情報

• CRID: 1390282681451637760
• NII論文ID: 110002693401
• NII書誌ID: AA10824164
• DOI: 10.1271/bbb.65.1697
• COI: 1:CAS:528:DC%2BD3MXmslSlt7k%3D
• ISSN: 13476947
• ISSN: 09168451
• NDL書誌ID: 5902729
• PubMed: 11577706
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5902729
• Web Site: http://www.tandfonline.com/doi/pdf/10.1271/bbb.65.1697
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可