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  • 學位論文

負載雙核錯合物至中孔洞性奈米粒子以模擬超氧歧化酵素之活性

Immobilization of Dinuclear Complexes in Mesoporous Silica Nanoparticle Mimicking the Superoxide Dismutases Activity

指導教授 : 牟中原

摘要


對於模擬超氧歧化酵素(superoxide dismutase)的模型,用咪唑基(imidazole)來橋接雙金屬的錯合物逐漸受到注目。超氧歧化酵素是一種可以在有機體內進行催化歧化作用的酵素,而歧化作用主要是將超量的超氧陰離子轉化形成氧氣和二氧化氫。 歧化反應: M(n+1)+-SOD + O2-• → M(n+)-SOD + O2 (1) Mn+-SOD + O2-• + 2H+ → M(n+1)+-SOD + H2O2 (2) 一系列用咪唑基橋接的同核和異核雙金屬錯合物,[(Bipy)2Cu-Im-Cu(Bipy)2](ClO4)3.CH3OH, [(Bipy)2Cu-Im-Zn(Bipy)2](ClO4)3.CH3OH, [(Bipy)2Cu-E-Im-Cu(Bipy)2](BF4)3, [(Bipy)2Cu-E-Im-Zn(Bipy)2](BF4)3 被合成出來。(Bipy = 2,2'-聯吡啶, E-Im = 2-乙基咪唑) 這些合成的錯合物可以藉由元素分析,感應耦合電漿質譜分析,紫外光-可見光光譜分析和電子順磁共振光譜來鑑定。而模擬超氧歧化酵素的活性則是透過NBT assay 活性測試實驗來決定。這些錯合物可以在生物pH環境下來催化超氧陰離子的歧化作用。 最後,我們將這些錯合物負載至中孔洞二氧化矽奈米粒子(MSN)來當作自然界中銅鋅超氧歧化酵素可能的環境。我們也另外準備了含鋁的(Al-MSN)和有帶正電荷官能基(TMAC)嫁接的中孔洞奈米粒子(Al-MSN-N+)來比較之間的活性並且來印證我們的假設。在這邊,固態中孔洞奈米粒子在模擬銅鋅超氧歧化酵素的架構中,主要是扮演骨架保護的角色。光譜分析研究可以使我們更進一步建立中孔洞奈米粒子的奈米結構和附載在這些奈米材料來模擬超氧歧化酵素活性彼此之間的關係。

並列摘要


Binuclear imidazolate-bridged copper(Ⅱ) complexes have attracted much attention as models for mimicking superoxide dismutase (SOD). SOD is a class of enzymes that can catalyze the dismutation of excess superoxide radical (O2-•) into oxygen (O2) and hydrogen peroxide (H2O2) in organisms. Dismutation reaction: M(n+1)+-SOD + O2-• → M(n+)-SOD + O2 (1) Mn+-SOD + O2-• + 2H+ → M(n+1)+-SOD + H2O2 (2) A series of homo- and hetero- dinuclear imidazolate-bridged complexes, [(Bipy)2Cu-Im-Cu(Bipy)2](ClO4)3.CH3OH, [(Bipy)2Cu-Im-Zn(Bipy)2](ClO4)3.CH3OH, [(Bipy)2Cu-E-Im-Cu(Bipy)2](BF4)3, [(Bipy)2Cu-E-Im-Zn(Bipy)2](BF4)3 (Bipy = 2,2'-Bipyridyl, E-Im = 2-ethylimidazole), were synthesized. The mimic complexes were characterized by elemental analysis (EA), ICP-MS, UV-VIS and EPR. The SOD-like activities were determined via decay of superoxide ions (O2-•) by a NBT (NitroBlue Tetrazolium) assay. These complexes catalyzed the dismutation of superoxide radical (O2-•) at biological pH. Finally, we immobilized these complexes in mesoporous silica nanoparticles (MSN) as a possible model for native CuZnSOD enzyme. We also prepared Al-MSN and Al-MSN-N+ to compare the activities and confirm our hypothesis. The MSN solids mimic the protein framework of CuZnSOD which plays a role as skeleton protection here. Spectroscopic studies further allowed us to establish the structure reactivity relationship between the nanostructure of MSN and efficacy of SOD-like of MSN, Al-MSN and Al-MSN-N+.

參考文獻


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