2003 Fiscal Year Annual Research Report

補酵素類縁体の電子移動反応制御とその応用

Research Project

Project/Area Number	01J00471
Research Institution	Osaka University
Principal Investigator	大久保敬大阪大学, 大学院・工学研究科, 特別研究員(PD)
Keywords	電子移動 / 電荷分離 / 光合成 / 光誘起 / 酸素化 / 補酵素 / フラーレン / 連結分子
Research Abstract	電子移動反応は生体内において最も基本的かつ重要な反応の1つである。これまで種々の補酵素類縁体の電子移動反応機構を解明し、反応場(溶媒、配位環境)を変えることによってその反応性を制御できることを明らかにしてきた。本課題研究では、さらに種々の金属イオン及び錯体を触媒として用いてこれらの電子移動反応を制御し、酵素活性に匹敵あるいはしのぐ人工酵素系を構築することを目的とするものであった。金属イオンを用いた電子移動制御については昨年度まででほぼ完了している。そこで本年度は生体において非常に重要な電子伝達物質であるニコチンアデニンジヌクレオチド(NAD)カチオン類縁体である9-フェニル-10-メチルアクリジニウムイオンを用いるとp-キシレンやp-シアノトルエンなどのトルエン誘導体を高選択的・高収率でアルデヒドへと光酸素化出来ることを見いだした(J.Am.Chem.Soc.2003,125,12850)。また、10-メチルアクリジニウムイオンの9位にメシチレンで置換し光照射を行うと分子内電子移動反応が効率よく進行し電荷分離状態が生成した。この電荷分離寿命・および電荷分離エネルギーの値は天然の光合成系を遙かに超えるものであることを見いだした(J.Am.Chem.Soc.2004,126,1600)。また、超寿命電荷分離状態の生成という点では120秒という天然の100倍近い電荷分離状態を持つ電子供与体・受容体連結分子の開発にも成功した(Angew.Chem.,Int.Ed.2004,43,853)。この3報が本年度のもっとも特筆すべき論文だがこれら以外にも30報あまりの投稿論文を発表した。

Research Products
(29 results)

All Other

All Publications (29 results)

[Publications] Kei Ohkubo et al.: "A planar catechin analogue having a more negative oxidation potential than (+)-catechin as an electron transfer antioxidant against a peroxyl radical."Chemical Research in Toxicology. 17・1. 26-31 (2004)
[Publications] Kei Ohkubo et al.: "Electron-Transfer State of 9-Mesityl-10-methylacridinium Ion with a Much Longer Lifetime and Higher Energy Than That of the Natural Photosynthetic Reaction Center."Journal of the American Chemical Society. 126・6. 1600-1601 (2004)
[Publications] Kei Ohkubo et al.: "Production of an ultra-long-lived charge-separated state in a zinc chlorin-C_<60> dyad by one-step photoinduced electron transfer."Angewandte Chemie, International Edition. 43・7. 853-856 (2004)
[Publications] Kei Ohkubo et al.: "Quantitative evaluation of d-π interaction in copper(I) complexes and control of copper(I)-dioxygen reactivity."Chemistry--A European Journal. 10・1. 237-246 (2004)
[Publications] Kei Ohkubo et al.: "A Planar Catechin Analogue as a Promising Antioxidant with Reduce Prooxidant Activity."Chemical Research in Toxicology. 16・1. 81-86 (2003)
[Publications] Kei Ohkubo et al.: "A ruthenium pterin complex showing proton-coupled electron transfer : synthesis and characterization."Angewandte Chemie, International Edition. 42・40. 4951-4954 (2003)
[Publications] Kei Ohkubo et al.: "Catalysis of rare-earth ions on electron transfer reduction of p-benzoquinones and the effects of counter anions"Kidorui. 42. 76-77 (2003)
[Publications] Kei Ohkubo et al.: "Diels-Alder Reactions of Anthracenes with Dienophiles via Photoinduced Electron Transfer"Journal of Physical Chemistry A. 107・28. 5412-5418 (2003)
[Publications] Kei Ohkubo et al.: "Driving force dependence of intermolecular electron-transfer reactions of fullerenes"Chemistry--A European Journal. 9・7. 1585-1593 (2003)
[Publications] Kei Ohkubo et al.: "Driving Force Dependence of Photoinduced Electron Transfer Dynamics of Intercalated Molecules in DNA"Journal of Physical Chemistry B. 107・45. 1520-6106 (2003)
[Publications] Kei Ohkubo et al.: "Effects of intramolecular hydrogen bonding on electron transfer properties of bisphenol derivatives in relation to their developing properties in silver salt photothermograghic systems"Nippon Shashin Gakkaishi. 66・5. 491-496 (2003)
[Publications] Kei Ohkubo et al.: "Efficient radical scavenging ability of artepillin C, a major component of Brazilian propolis, and the mechanism"Organic & Biomolecular Chemistry. 1・9. 1452-1454 (2003)
[Publications] Kei Ohkubo et al.: "Electron transfer properties of bisphenol derivatives in relation to their developing properties in silver salt photothermographic systems"Journal of Imaging Science and Technology. 47・2. 124-132 (2003)
[Publications] Kei Ohkubo et al.: "Electron transfer reduction of fluorofullerenes, C_<60>F_<18> and C_3C_<60>F_<36>"Proceedings-Electrochemical Society. 2003-15. 20-30 (2003)
[Publications] Kei Ohkubo et al.: "Enhancement of light harvesting and photocurrent generation by ITO electrodes modified with meso, meso-linked porphyrin oligomers"Nano Letters. 3・3. 409-412 (2003)
[Publications] Kei Ohkubo et al.: "Fast self-exchange electron transfer and delocalization of unpaired electron between zinc porphyrin radical cations and zinc porphyrins"Journal of Porphyrins and Phthalocyanines. 7・4&5. 328-336 (2003)
[Publications] Kei Ohkubo et al.: "Fluorinated photosensitizers : synthesis, photophysical, electrochemical, intracellular localization, in vitro photosensitizing efficacy and determination of tumor-uptake by ^<19>F in vivo NMR spectroscopy"Tetrahedron. 59・50. 10059-10073 (2003)
[Publications] Kei Ohkubo et al.: "Long-lived charge-separated state produced by photoinduced electron transfer in a zinc imidazoporphyrin-C_<60> dyad"Organic Letters. 5・15. 2719-2721 (2003)
[Publications] Kei Ohkubo et al.: "Metal-Centered Photoinduced Electron Transfer Reduction of a Gold(III) Porphyrin Cation Linked with a Zinc Porphyrin to Produce a Long-Lived Charge-Separated State in Nonpolar Solvents"Journal of the American Chemical Society. 125・49. 14984-14985 (2003)
[Publications] Kei Ohkubo et al.: "Oxidation mechanism of phenols by dicopper-dioxygen (Cu(II)/O_2) complexes"Journal of the American Chemical Society. 125・36. 11027-11033 (2003)
[Publications] Kei Ohkubo et al.: "Oxygenation of a-Methylstyrene with Molecular Oxygen, Catalyzed by 10-Methylacridinium Ion via Photoinduced Electron Transfer"Journal of Physical Chemistry A. 107・22. 4339-4346 (2003)
[Publications] Kei Ohkubo et al.: "Quantitative Evaluation of Lewis Acidity of Metal Ions with Different Ligands and Counterions in Relation to the Promoting Effects of Lewis Acids on Electron Transfer Reduction of Oxygen"Journal of Organic Chemistry. 68・12. 4720-4726 (2003)
[Publications] Kei Ohkubo et al.: "Rational Design Principle for Modulating Fluorescence Properties of Fluorescein-Based Probes by Photoinduced Electron Transfer"Journal of the American Chemical Society. 125・28. 8666-8671 (2003)
[Publications] Kei Ohkubo et al.: "Remarkable effects of counter ions on scandium ion-promoted electron transfer reactions"Chemical Communications. 9. 1070-1071 (2003)
[Publications] Kei Ohkubo et al.: "Reversed effects of DNA on hydride transfer and electron transfer reactions of acridinium and quinolinium ions"Chemical Communications. 15. 1886-1887 (2003)
[Publications] Kei Ohkubo et al.: "Role of Electron-Transfer Processes in Reactions of Diarylcarbenium Ions and Related Quinone Methides with Nucleophiles"Journal of the American Chemical Society. 125・36. 10906-10912 (2003)
[Publications] Kei Ohkubo et al.: "Selective Oxygenation of Ring-Substituted Toluenes with Electron-Donating and -Withdrawing Substituents by Molecular Oxygen via Photoinduced Electron Transfer"Journal of the American Chemical Society. 125・42. 12850-12859 (2003)
[Publications] Kei Ohkubo et al.: "Structure and photoelectrochemical properties of ITO electrodes modified with self-assembled monolayers of meso, meso-linked porphyrin oligomers"Journal of Porphyrins and Phthalocyanines. 7・4&5. 296-312 (2003)
[Publications] Kei Ohkubo et al.: "Ultrafast Photodynamics of Exciplex Formation and Photoinduced Electron Transfer in Porphyrin-Fullerene Dyads Linked at Close Proximity"Journal of Physical Chemistry A. 107・42. 8834-8844 (2003)

2003 Fiscal Year Annual Research Report

補酵素類縁体の電子移動反応制御とその応用

Principal Investigator

大久保 敬 大阪大学, 大学院・工学研究科, 特別研究員(PD)

Research Products

[Publications] Kei Ohkubo et al.: "A planar catechin analogue having a more negative oxidation potential than (+)-catechin as an electron transfer antioxidant against a peroxyl radical."Chemical Research in Toxicology. 17・1. 26-31 (2004)

[Publications] Kei Ohkubo et al.: "Electron-Transfer State of 9-Mesityl-10-methylacridinium Ion with a Much Longer Lifetime and Higher Energy Than That of the Natural Photosynthetic Reaction Center."Journal of the American Chemical Society. 126・6. 1600-1601 (2004)

[Publications] Kei Ohkubo et al.: "Production of an ultra-long-lived charge-separated state in a zinc chlorin-C_<60> dyad by one-step photoinduced electron transfer."Angewandte Chemie, International Edition. 43・7. 853-856 (2004)

[Publications] Kei Ohkubo et al.: "Quantitative evaluation of d-π interaction in copper(I) complexes and control of copper(I)-dioxygen reactivity."Chemistry--A European Journal. 10・1. 237-246 (2004)

[Publications] Kei Ohkubo et al.: "A Planar Catechin Analogue as a Promising Antioxidant with Reduce Prooxidant Activity."Chemical Research in Toxicology. 16・1. 81-86 (2003)

[Publications] Kei Ohkubo et al.: "A ruthenium pterin complex showing proton-coupled electron transfer : synthesis and characterization."Angewandte Chemie, International Edition. 42・40. 4951-4954 (2003)

[Publications] Kei Ohkubo et al.: "Catalysis of rare-earth ions on electron transfer reduction of p-benzoquinones and the effects of counter anions"Kidorui. 42. 76-77 (2003)

[Publications] Kei Ohkubo et al.: "Diels-Alder Reactions of Anthracenes with Dienophiles via Photoinduced Electron Transfer"Journal of Physical Chemistry A. 107・28. 5412-5418 (2003)

[Publications] Kei Ohkubo et al.: "Driving force dependence of intermolecular electron-transfer reactions of fullerenes"Chemistry--A European Journal. 9・7. 1585-1593 (2003)

[Publications] Kei Ohkubo et al.: "Driving Force Dependence of Photoinduced Electron Transfer Dynamics of Intercalated Molecules in DNA"Journal of Physical Chemistry B. 107・45. 1520-6106 (2003)

[Publications] Kei Ohkubo et al.: "Effects of intramolecular hydrogen bonding on electron transfer properties of bisphenol derivatives in relation to their developing properties in silver salt photothermograghic systems"Nippon Shashin Gakkaishi. 66・5. 491-496 (2003)

[Publications] Kei Ohkubo et al.: "Efficient radical scavenging ability of artepillin C, a major component of Brazilian propolis, and the mechanism"Organic & Biomolecular Chemistry. 1・9. 1452-1454 (2003)

[Publications] Kei Ohkubo et al.: "Electron transfer properties of bisphenol derivatives in relation to their developing properties in silver salt photothermographic systems"Journal of Imaging Science and Technology. 47・2. 124-132 (2003)

[Publications] Kei Ohkubo et al.: "Electron transfer reduction of fluorofullerenes, C_<60>F_<18> and C_3C_<60>F_<36>"Proceedings-Electrochemical Society. 2003-15. 20-30 (2003)

[Publications] Kei Ohkubo et al.: "Enhancement of light harvesting and photocurrent generation by ITO electrodes modified with meso, meso-linked porphyrin oligomers"Nano Letters. 3・3. 409-412 (2003)

[Publications] Kei Ohkubo et al.: "Fast self-exchange electron transfer and delocalization of unpaired electron between zinc porphyrin radical cations and zinc porphyrins"Journal of Porphyrins and Phthalocyanines. 7・4&5. 328-336 (2003)

[Publications] Kei Ohkubo et al.: "Fluorinated photosensitizers : synthesis, photophysical, electrochemical, intracellular localization, in vitro photosensitizing efficacy and determination of tumor-uptake by ^<19>F in vivo NMR spectroscopy"Tetrahedron. 59・50. 10059-10073 (2003)

[Publications] Kei Ohkubo et al.: "Long-lived charge-separated state produced by photoinduced electron transfer in a zinc imidazoporphyrin-C_<60> dyad"Organic Letters. 5・15. 2719-2721 (2003)

[Publications] Kei Ohkubo et al.: "Metal-Centered Photoinduced Electron Transfer Reduction of a Gold(III) Porphyrin Cation Linked with a Zinc Porphyrin to Produce a Long-Lived Charge-Separated State in Nonpolar Solvents"Journal of the American Chemical Society. 125・49. 14984-14985 (2003)

[Publications] Kei Ohkubo et al.: "Oxidation mechanism of phenols by dicopper-dioxygen (Cu(II)/O_2) complexes"Journal of the American Chemical Society. 125・36. 11027-11033 (2003)

[Publications] Kei Ohkubo et al.: "Oxygenation of a-Methylstyrene with Molecular Oxygen, Catalyzed by 10-Methylacridinium Ion via Photoinduced Electron Transfer"Journal of Physical Chemistry A. 107・22. 4339-4346 (2003)

[Publications] Kei Ohkubo et al.: "Quantitative Evaluation of Lewis Acidity of Metal Ions with Different Ligands and Counterions in Relation to the Promoting Effects of Lewis Acids on Electron Transfer Reduction of Oxygen"Journal of Organic Chemistry. 68・12. 4720-4726 (2003)

[Publications] Kei Ohkubo et al.: "Rational Design Principle for Modulating Fluorescence Properties of Fluorescein-Based Probes by Photoinduced Electron Transfer"Journal of the American Chemical Society. 125・28. 8666-8671 (2003)

[Publications] Kei Ohkubo et al.: "Remarkable effects of counter ions on scandium ion-promoted electron transfer reactions"Chemical Communications. 9. 1070-1071 (2003)

[Publications] Kei Ohkubo et al.: "Reversed effects of DNA on hydride transfer and electron transfer reactions of acridinium and quinolinium ions"Chemical Communications. 15. 1886-1887 (2003)

[Publications] Kei Ohkubo et al.: "Role of Electron-Transfer Processes in Reactions of Diarylcarbenium Ions and Related Quinone Methides with Nucleophiles"Journal of the American Chemical Society. 125・36. 10906-10912 (2003)

[Publications] Kei Ohkubo et al.: "Selective Oxygenation of Ring-Substituted Toluenes with Electron-Donating and -Withdrawing Substituents by Molecular Oxygen via Photoinduced Electron Transfer"Journal of the American Chemical Society. 125・42. 12850-12859 (2003)

[Publications] Kei Ohkubo et al.: "Structure and photoelectrochemical properties of ITO electrodes modified with self-assembled monolayers of meso, meso-linked porphyrin oligomers"Journal of Porphyrins and Phthalocyanines. 7・4&5. 296-312 (2003)

[Publications] Kei Ohkubo et al.: "Ultrafast Photodynamics of Exciplex Formation and Photoinduced Electron Transfer in Porphyrin-Fullerene Dyads Linked at Close Proximity"Journal of Physical Chemistry A. 107・42. 8834-8844 (2003)

大久保敬大阪大学, 大学院・工学研究科, 特別研究員(PD)