MECHANISM OF OXYGEN ACTIVATION BY IRON-CHLORIN COMPLEXES AND THEIR REACTIVITIES.

铁-氯络合物的氧活化机制及其反应性。

• 批准号: 05453043
• 负责人: WATANABE Yoshihito
• 金额: $ 3.9万
• 依托单位: OKAZAKI NATIONAL RESEARCH INSTITUTES (1994)Kyoto University (1993)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453043/
• 关键词: chlorin; compound I; cation radical; cytochrome d; heme; Compound I; cytochrome d; 鉄クロリン錯体; 酵素モデル; 酸素活性化; 反応機構

Preparation and characterization of reaction intermediates observed or proposed in the catalytic cycle chlorin-containing heme enzymes. Catalases in Escherichia coli and Neurospora crassa possess iron chlorin prosthetic groups and catalyze dismutation of hydrogen peroxide. While a high-valent iron chlorin complex (chlorin compound I) is postulated to be a reaction intermediate in the catalytic cycle of these catalases, the high-valent chlorins have not been prepared and thus the details of chlorin compound I are still obscure. Thus, we have prepared the chlorin compound I by employing a sterically hindered chlorin model complex. The oxo-iron (IV) chlorin pi-cation radical has been successfully prepared.Models of oxo-iron (IV) chlorin complexes have been prepared and characterized in detail to elucidate the unusual properties of the intermediate of cytochrome d. The six-coordinated oxo-ferrylchorin complex exhibited an unusual splitting of the hyperfine-shifted pyrroline proton resonances in its NMR spectrum, suggestive of deformation of the pyrroline ring of the chlorin complex.The model complexes of the putative reaction intermediate, peroxo-Fe (III), have been synthesized. The peroxo complexes have electronics structures similar to those of the corresponding porphyrin complexes. However, unusual features have been observed in their deuterium NMR spectra, rationalized by large deformation of the pyrroline ring of the peroxo complexes.

含氯血红素酶催化循环中反应中间体的制备和表征。大肠杆菌和粗神经孢子虫的过氧化氢酶具有氯化铁假基并催化过氧化氢的畸变。虽然高价氯化铁络合物（氯化合物I）被认为是这些过氧化氢酶催化循环中的反应中间体，但高价氯尚未制备出来，因此氯化合物I的细节仍然不清楚。因此，我们利用位阻氯模型配合物制备了氯化合物I。成功制备了氧铁（IV）氯离子自由基。为了阐明细胞色素d中间体的特殊性质，我们制备了氧-铁（IV）氯配合物模型，并对其进行了详细的表征。六配位氧-铁-氯配合物在其核磁共振谱中表现出异常的超精细位移吡咯啉质子共振分裂，表明氯配合物的吡咯啉环发生了变形。合成了假定的反应中间体过氧铁（III）的模型配合物。过氧配合物的电子结构与相应的卟啉配合物相似。然而，在它们的氘核磁共振光谱中观察到不寻常的特征，这是由过氧配合物的吡咯环的大变形所解释的。

项目成果

Ozawa, S.; Watanabe, Y.; Morishima, I.: "NMR Studies of pi-Cation Radical Complexes of Iron (III) and Oxoiron (IV) Chlorins. Models for Reaction Intermediates of Chlorin-Containing Heme Enzymes." J.Am.Chem.Soc.116. 5832-5838 (1994)

小泽，S.；

Shinji Ozawa: "Spectroscopic Characterization of Peroxo-Iron(III)Chlorin Complexes.The First Model for a Reaction Intermediate of Cytochromed." Inorg.Chem.33. 306-313 (1994)

Shinji Ozawa：“过氧化铁 (III) 二氢卟酚复合物的光谱表征。细胞色素反应中间体的第一个模型。”

Ozawa,S.: "NMR Studies of π-Cation Radical Complexes of Iron (III) and Oxoiron (IV) Chlorins. Models for Reaction Intermediates of Chlorin-Containing Heme Enzymes." J.Am.Chem.Soc.116. 5832-5838 (1994)

Ozawa, S.：“铁 (III) 和 Oxoiron (IV) 二氢卟酚的 π-阳离子自由基复合物的核磁共振研究。含二氢卟酚血红素酶的反应中间体模型。J.Am.Chem.Soc.116-” 5838 (1994)

Tsurumaki, H.; Watanabe, Y.; Morishima, I.: "Three Isoelectronic Structures of One Electron Oxidized Nickel Porphyrins" Inorg.Chem.33. 4186-4188 (1994)

鹤卷，H.；

Ozawa, S.; Watanabe, Y.; Morishima, I.: "Spectroscopic Characterization of Peroxo-Iron (III) Chlorin Complexes. The First Model for a Reaction Intermediate of Cytochrome d." Inorg.Chem.33. 306-313 (1994)

小泽，S.；