在水溶液中通过二核铜复合体激活过氧化和二氧化:通过内部电子转移启动的基生成
Qing Zhu1, Yuxiang Lian, Sunita Thyagarajan
1Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
Journal of the American Chemical Society
|April 25, 2008
概括
双核铜 (II) 复合物 (CuII2Nn) 通过产生基或基基基来选择性地分裂DNA. 这通过分子内电子转移机制发生,而不是与金属-氧中间体直接反应.
科学领域:
- 生物有机化学 生物有机化学
- 基因分裂机制的DNA裂变机制
- 激进化学 激进化学是什么
背景情况:
- 双核铜 (II) 复合体 (CuII2Nn) 显示有选择性的DNA裂变活性.
- 反应性取决于复杂的结构 (双核或单核) 和反应条件 (/O2或H2O2).
研究的目的:
- 阐明由CuII2Nn复合体介导的DNA裂变的机制.
- 为了确定对DNA损伤负责的反应性物种.
主要方法:
- 谱学研究以表征反应中间体.
- 动力分析以确定反应途径.
- 调查与电子捐赠者的中间反应性.
主要成果:
- 在反应条件下,从CuII2Nn复合物中生成一种中间体.
- 这种中间体分解,产生基 (OH) 基和连接体降解产物.
- 中间体的衰变涉及分子内电子转移,产生OH基和基于连接体的基.
- 这些基因导致了DNA裂变,而不是直接的金属-氧相互作用.
结论:
- 通过CuII2Nn复合体的DNA裂变是由OH基或基于连接体的基调介导的.
- 该机制涉及从连接体到金属氧中心的分子内部电子转移.
- 单核复合体和CuII2N3没有这种选择性反应性.
相关概念视频
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
Radical Autoxidation
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Radical Anti-Markovnikov Addition to Alkenes: Mechanism
The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy radical...
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy radical...
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