WEKO3
アイテム
Tunneling in the Scavenging Reaction of Water-Solubilized 2,2-Diphenyl-1-picrylhydrazyl Radical by Antioxidants in Aqueous Buffer Solutions
https://repo.qst.go.jp/records/78936
https://repo.qst.go.jp/records/7893613e7fbd6-a967-4b69-9d3e-b6d294e822ca
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2020-02-10 | |||||
| タイトル | ||||||
| タイトル | Tunneling in the Scavenging Reaction of Water-Solubilized 2,2-Diphenyl-1-picrylhydrazyl Radical by Antioxidants in Aqueous Buffer Solutions | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Nakanishi, Ikuo
× Nakanishi, Ikuo× Shoji, Yoshimi× Ohkubo, Kei× Ozawa, Toshihiko× Ken-ichiro, Matsumoto× Fukuzumi, Shunichi× Nakanishi, Ikuo× Shoji, Yoshimi× Ohkubo, Kei× Ozawa, Toshihiko× Matsumoto, Kenichiro |
|||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Hydrogen-atom transfer in the radical-scavenging reactions of antioxidants has attracted much attention with regard to quantum mechanical behaviors in biological reactions. Recently, we have succeeded in solubilizing water-insoluble 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in water using beta-cyclodextrin (beta-CD). We report herein the kinetic isotope effect in the DPPH radical-scavenging reaction by antioxidants in an aqueous buffer solution. Upon mixing of Trolox, a water-soluble analog of vitamin E, with the beta-CD-solubilized DPPH radical in a phosphate buffer solution (0.05 M, pH 7.0) at 298 K, the absorption band at 527 nm due to the DPPH radical immediately decreased. From the time course change in the absorbance at 527 nm, the second-order rate constant (kH) for this reaction was determined to be 14000 M^-1 s^-1. When H2O was replaced by D2O to prepare a phosphate buffer solution (0.05 M, pD 7.0), the second-order rate constant (kD) was significantly decreased to be 2000 M^-1 s^-1. Thus, the kinetic isotope effect (kH/kD) of 7.4 was obtained, suggesting that tunneling may play a role in the hydrogen atom transfer from Trolox to the DPPH radical in a phosphate buffer solution. |
|||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | Oxygen Radicals, Gordon Research Conference | |||||
| 発表年月日 | ||||||
| 日付 | 2020-02-05 | |||||
| 日付タイプ | Issued | |||||
