定数感应分子的化:动力学和转换途径
N G Keltsch1, C Dietrich2, A Wick2
1Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068, Koblenz, Germany; Universität Koblenz, Universitätsstraße 1, 56070, Koblenz, Germany.
Chemosphere
|December 7, 2024
概括
化有效降解像AHL和HHQ这样的定数感应分子 (QSM),抑制细菌致病性和生物膜形成. 了解这些反应是消毒策略的关键.
科学领域:
- 环境化学环境化学
- 微生物学 微生物学
- 水处理 处理水的方法
背景情况:
- 定数感应 (QS) 调节细菌的致病性和生物膜的形成.
- 质量感应分子 (QSMs) 对于格拉姆阴性细菌的QS信号传递至关重要.
- 化对QSM的影响在消毒研究中未得到充分研究.
研究的目的:
- 阐明在暴露于自由可用的 (FAC) 时,N-同类素乳 (AHLs) 和2--4- (HHQ) 的反应动力学和转化途径.
- 调查pH和反应性物种对QSM降解的影响.
- 确定QSM转化产品并提出反应机制.
主要方法:
- 对QSMs (pC-AHL,C14:1-AHL,HHQ,3-Oxo-C14-AHL) 与FAC.反应的动力学研究.
- 对反应顺序和pH取决于速度常数的分析.
- 使用高分辨率质谱测量 (非目标和可疑查) 识别转化产品.
主要成果:
- 通过FAC观察到PC-AHL,C14:1-AHL,HHQ和3-Oxo-C14-AHL的完全降解.
- 对FAC的反应顺序从1.19到1.62不等,表明复杂的反应机制.
- 第一阶速常数是pH依赖的,其变化受反应性物种和/酸盐比率的影响. 确定了29种转化产品.
结论:
- 化有效地转化关键的QSM,可能破坏QS控制的细菌过程,如生物膜形成.
- 识别的反应机制为化过程中的QSM行为提供了洞察力.
- 这些发现可以为针对QS介导的细菌活动的消毒策略提供信息.
相关概念视频
Gene Regulation in Microbial Communities: Quorum Sensing
1
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
1
Bacterial Signaling
31.5K
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
31.5K
SN2 Reaction: Kinetics
8.2K
Kinetic Studies and Significance
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
8.2K
Oxidation 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
Radical 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
Radical Substitution: Allylic Chlorination
2.2K
Typically, when alkenes react with halogens at low temperatures, an addition reaction occurs. However, upon increasing the temperature or under reaction conditions that form radicals, providing a low but steady concentration of halogen radicals, allylic substitution reaction is favored. This is because allylic hydrogens are very reactive as the formed intermediate is resonance stabilized. For example, when propene is treated with chlorine in the gas phase at 400 °C, it undergoes allylic...
2.2K


