O2の活性化は,ビス・イミノ・ピリジン・鉄・II・チオラート複合体によるものです
Yosra M Badiei1, Maxime A Siegler, David P Goldberg
1Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21212, United States.
Journal of the American Chemical Society
|January 7, 2011
まとめ
新しい鉄複合体はシステイン酸化酸化酵素 (CDO) 活性を模倣する. 酸化反応は,チオラートリガンドの位置が,鉄または硫黄が酸化されるかどうかを決定し,CDO酵素機構に影響することを示しています.
科学分野:
- バイオ・オーガニック化学 バイオ・オーガニック化学
- 有機金属化学 有機金属化学
- 酵素ミミクリは,酵素ミミクリを
背景:
- システイン二酸化酵素酶 (CDO) は,システインの酸化をシステイン硫酸に触媒する重要な酵素です.
- CDOは,その触媒的機能のために保存された (His) ((3) Fe ((II)) 活性サイトを使用します.
- CDOのメカニズムを理解するには,その活性サイト環境を複製するバイオミメティックモデルが必要です.
研究 の 目的:
- システイン・ダイオキシゲネーゼのモデルとして,新しい鉄 (II) -チオラート複合体を合成し,特徴づけること.
- これらのモデルの分子酸素 (O(2) との反応性を調査する.
- O(2) アクティベーションと製品形成におけるチオラートリガンドの役割を明らかにする.
主な方法:
- ビス・イミノ・ピリジン (BIP) リガンドによる鉄{II}-チオラート複合体の合成.
- 合成された複合体の反応は,制御された条件下でO ((2)) と反応する.
- 反応産物を特徴付けるために,光譜分析 (例えば,NMR,UV-Vis) と (18) O同位体ラベル付けの研究を行う.
- Fe (III) / Fe (II) レドックスポテンシャルを決定するための電気化学の研究.
主要な成果:
- 2つの鉄・チオラート複合体である[BIP]Fe[II]SPh[Cl] (1) と[BIP]Fe[II]SPh[OTf] (2) が,成功裏に作製されました.
- 複合体1とO(2) の反応により,鉄(IV) -オクソ種が生み出され,Fe-酸素化を示した.
- 複合体2がO(2) と反応すると,直接のS-酸素化がスルフォナート産物となる.
- (18) O同位体研究により,酸化経路が確認された.
結論:
- シアロ酸リガンドの位置づけは,これらのFe (II) 複合体によるO (−2) 活性化の結果を決定する上で決定的に重要です.
- これらのモデルは,CDOメカニズムに関連する異なるFe-酸素化とS-酸素化経路を示しています.
- シアロ酸リガンドは,O ((2)) の反応性にとって不可欠であり,鉄中心の酸化還元能力に影響を与えます.
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