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反应中间体的制备与表征。大肠杆菌和粗糙脉孢菌中的过氧化氢酶具有铁二氢卟酚辅基并催化过氧化氢的歧化。虽然高价铁二氢卟酚络合物（二氢卟酚化合物I）被假定为这些过氧化氢酶的催化循环中的反应中间体，但高价二氢卟酚尚未制备，因此二氢卟酚化合物I的细节仍然不清楚。因此，我们已经通过使用空间位阻二氢卟酚模型络合物制备了二氢卟酚化合物I。成功地制备了氧代铁（IV）二氢卟酚π-阳离子自由基，并制备了氧代铁（IV）二氢卟酚配合物模型，详细地表征了其结构，阐明了细胞色素d中间体的特殊性质。六配位的氧代-ferrylchorin配合物在其NMR谱中表现出不寻常的超精细位移的吡咯啉质子共振分裂，暗示了二氢卟啉配合物的吡咯啉环的变形。已经合成了假定的反应中间体过氧-Fe（III）的模型配合物。过氧配合物具有与相应卟啉配合物类似的电子结构。然而，不寻常的功能已被观察到在其氘NMR光谱，合理化的大变形的吡咯啉环的过氧配合物。

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.；