Investigation of Hydrated Electron Quenching by Quinone Compounds under Micellar Reaction Environment

胶束反应环境下醌类化合物水合电子猝灭的研究

• 批准号: 10640562
• 负责人: NAKAGAWA Kouichi
• 金额: $ 1.15万
• 依托单位: Fukushima Medical University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640562/
• 关键词: Micelle; EPR; Quinone; Free Radical; UV; Spin Label; Antioxidant; Phenol; UV照射

We have studied the hydrated electron (e_<aq>^-) quenching by idebenone (IDB) and the related compound (CoQ_0) in SDS and SOS micellar solutions with 1-propanol (1-PrOH) addition. UV irradiation of IDB with the long side chain in 1-PrOH produced the neutral radical, whereas in the presence of an electron donor (DABCO) the anion radical was formed. On the other hand, UV irradiation of CoQ_0 without the side chain produced the anion radical both in the presence and in the absence of DABCO.In micellar solutions, both compounds produced anion radicals but the EPR (electron paramagnetic resonance) intensity of the IDB radical was very weak even in the presence of DABCO.When 1-PrOH was added to the micellar solution, the signal intensity of the IDB radical increased approximately seven-fold. The effective e_<aq>^- quenching by IDB to form the radical results in decrease of micellar charge density. Therefore, the results obtained suggest that the benzoquinone nucleus of IDB can locate in the … More polar region of the micelle. Furthermore, it was found that IDB quenched e_<aq>^- by the pseudo-first-order kinetic with the rate of 2.1x10^6 sec^<-1> in the micelllar system.Next, the intermediate radicals generated by continuous UV and pulsed UV laser irradiation of antioxidant sesamol in aqueous solutions were investigated. Radical species with the intensity ratio of 1 : 4 : 6 : 4 : 1 was observed using continuous wave Electron Paramagnetic Resonance (CW EPR) with continuous UV irradiation. In order to observe the intermediate radical right after the excitation, Fourier Transform EPR (FT EPR) was used. Trace amount of the same radical was also detected by FT EPR with pulsed UV laser. Based on the hyperfine coupling constant (2.3 G) and g-value (2.0048) together with FT EPR results, this radical was found to be a benzoquinone anion radical. The radical might be produced via multi-step reactions of the excited sesamol in aqueous solution and was stable for at least several minutes. FT EPR showed the detailed behavior of the radicals. Characterization of the intermediate is important to evaluate the antioxidant sesamol. Less

本文研究了<aq>艾地苯醌（IDB）及其相关化合物（CoQ_0）在SDS和SOS胶束溶液中加入1-丙醇（1-PrOH）对水合电子（e_ ^-）的猝灭作用。紫外线照射IDB与长侧链在1-PrOH产生的中性自由基，而在存在的电子供体（DABCO）的阴离子自由基形成。在胶束溶液中，无侧链的CoQ_0在DABCO存在和不存在下均产生阴离子自由基，但EPR不产生阴离子自由基（电子顺磁共振）强度的IDB自由基是非常弱的，即使在DABCO的存在下。IDB基团的信号强度增加了约7倍。IDB有效地猝灭e <aq>^-形成自由基，导致胶束电荷密度降低。因此，所获得的结果表明，IDB的苯醌核可以位于 ...更多信息 胶束的极性区域。在胶束体系中，IDB对e_（<aq>^-）的猝灭符合准一级反应动力学，猝灭速率为2.1 × 10^6秒^<-1>。用连续波电子顺磁共振（CW EPR）和连续紫外光照射观察到强度比为1：4：6：4：1的自由基物种。为了在激发后立即观察中间自由基，使用傅里叶变换EPR（FT EPR）。用脉冲紫外激光的FT EPR也检测到痕量的相同自由基。基于超精细耦合常数（2.3 G）和g值（2.0048）以及FT EPR结果，发现该自由基是苯醌阴离子自由基。该自由基可能是通过激发的芝麻酚在水溶液中的多步反应产生的，并且至少稳定几分钟。FT EPR研究了自由基的详细行为。中间体的表征对于评价抗氧化剂芝麻素是重要的。少

项目成果

K.Nakagawa, and T.Tsuchihashi: "Investigation of Motive Effects of the Antioxidant Quinone in Micellar Solutions"Magn.Reson.Jpn.. 10. 155-158 (2000)

K.Nakakawa 和 T.Tsuchihashi：“胶束溶液中抗氧化醌的动机效应的研究”Magn.Reson.Jpn.. 10. 155-158 (2000)

H.Bussandri, et al.: "FT-EPR Study of the pH Dependence of the Photochemistry of Sesamol in Aqueous Solution"Appl.Magn.Reson.. 17/4. 577-587 (1999)

H.Bussandri 等人：“水溶液中芝麻酚光化学的 pH 依赖性的 FT-EPR 研究”Appl.Magn.Reson.. 17/4。

K.Nakagawa: "Effect of Heavy Ion Irradiation on Sucrose"Chem.Letts.. 422-423 (2000)

K.Nakakawa：“重离子照射对蔗糖的影响”Chem.Letts.. 422-423 (2000)

中川公一: "重粒子線照射で生成するスクロースラジカル"放射線科学. 43/7. 202-204 (2000)

Koichi Nakakawa：“重粒子束照射产生的蔗糖自由基”放射线科学 202-204 (2000)。

中川公一: "抗酸化性セサモールの水溶液中における特異な挙動"磁気共鳴と医学. 11(in press). (2001)

中川浩一：“抗氧化剂芝麻酚在水溶液中的特殊行为”《磁共振与医学》11（出版中）。