通过性抗氧化剂模拟碳中心蛋白质基的修复
Max Walton-Raaby1,2, Tyler Floen1,3, Nelaine Mora-Diez1
1Department of Chemistry, Thompson Rivers University, Kamloops, BC V2C 0C8, Canada.
Antioxidants (Basel, Switzerland)
|November 27, 2024
概括
这项研究研究了类抗氧化剂如何修复氧化应激损伤. 虽然许多反应是有利的,但只有一个抗氧化剂显示了生物学相关的修复率,突出了动力学分析的必要性.
科学领域:
- 计算化学的计算化学
- 生物化学 生物化学
- 药用化学 医学化学
背景情况:
- 氧化应激与众多疾病有关,使其预防和修复对医学进步至关重要.
- 了解抗氧化剂修复的分子机制对于开发有效的治疗策略至关重要.
研究的目的:
- 为了研究20种性抗氧化剂对蛋白质损伤 (白基) 的模型的修复反应的热力学和动力学.
- 为了比较正规原子转移 (f-HAT) 和单个电子转移 (SET) 修复路径的有效性.
- 评估贝尔-埃文斯-波兰尼原理在不同条件下的适用性.
主要方法:
- 使用M06-2X(SMD)/6-31++G(d,p) 理论水平进行量子化学计算.
- 在两个不同的溶剂环境中建模修复反应:水和乙酸.
- 分析反应热力学和动力学,包括速率常数计算.
主要成果:
- 所有研究的形式-原子转移 (f-HAT) 反应都是热力学上有利的.
- 只有一种性抗氧化剂在扩散极限中表现出速率常数,这表明其具有显著的生物相关性.
- 单电子转移 (SET) 被认为是这些的不太可能的修复途径.
- 贝尔-埃文斯-波兰尼原理在各种溶剂,修复点和抗氧化剂中应用时显示出局限性.
结论:
- 溶液中速率常数的动力计算对于评估理论抗氧化剂研究的生物学相关性至关重要.
- 热力学数据作为一个有用的初始选工具,但动力学数据对于最终的结论至关重要.
- 溶剂和抗氧化剂的选择显著影响修复反应的效率.
相关概念视频
01:20Radical Autoxidation
2.1K
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...
2.1K
01:10Radical Reactivity: Steric Effects
1.9K
The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified.
Along with electronic...
Along with electronic...
1.9K
01:17Oxidation of Phenols to Quinones
2.9K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
2.9K
01:11Radical Reactivity: Overview
2.1K
Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired...
2.1K
00:51Radical Formation: Elimination
1.7K
Another method of radical formation is the elimination process. It is the opposite of the addition route and is driven by the instability of the radical. For example, as depicted in Figure 1, dibenzoyl peroxide yields a pair of unstable radicals upon homolysis. Given its instability, this radical spontaneously undergoes elimination via a C–C bond cleavage to form a relatively more stable phenyl radical. The mechanism involves cleavage of the bond between the α and β positions...
1.7K
01:10Radical Chain-Growth Polymerization: Overview
2.4K
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
2.4K