合成 [2Fe-2S] 和 [4Fe-4S] 集群与氧化和酸盐醇的反应
Todd C Harrop1, Zachary J Tonzetich, Erwin Reisner
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|October 23, 2008
概括
氧化 (NO) 与铁硫集群发生反应,形成二甲酸铁复合物 (DNIC). 这项研究探讨了NO NO.
科学领域:
- 生物有机化学 生物有机化学
- 协调化学 协调化学
- 生物化学 生物化学
背景情况:
- 氧化 (NO) 与铁硫蛋白相互作用,导致集群降解和二甲酸铁复合物 (DNIC) 的形成.
- DNIC的形成可以改变酶活性,并激活生物系统中的调节通路.
研究的目的:
- 研究氧化和合成 [2Fe-2S] 和 [4Fe-4S] 集群之间的反应的基本化学成分.
- 阐明这些反应的途径和产物,提供对生物过程的洞察力.
主要方法:
- 合成 [2Fe-2S] 和 [4Fe-4S] 集群与气态氧化 (NO) 的反应.
- 反应产品的表征,包括X射线晶体学用于结构确定.
- 使用了三-S-酸醇 (Ph3CSNO) 作为另一种氧化来源.
主要成果:
- [2Fe-2S]集群与NO过量的反应产生了DNICs ([Fe(NO) 2 ((SR) 2)) 和元素硫.
- [4Fe-4S]集群与NO反应,在没有多余的硫酸盐的情况下形成鲁辛黑盐 ([Fe4S3(NO) [7](-)) .
- 存在足够的硫酸盐稳定了来自 [4Fe-4S] 集群的 DNIC 形成,与 Ph3CSNO 反射反应.
结论:
- 该研究表明,在生物背景下,铁硫集群与氧化的反应途径是合理的.
- 突出了硫酸盐与铁的比率在稳定二甲酸铁复合物的关键作用.
相关概念视频
Preparation and Reactions of Thiols
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
2° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
Nitrosation of Enols
The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.
Rate-Determining Steps
Relating Reaction Mechanisms
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
Preparation of Nitriles
One of the common methods to prepare nitriles is the dehydration of amides. This method requires strong dehydrating agents like phosphorous pentoxide or boiling acetic anhydride for converting amides to nitriles. Another reagent namely, thionyl chloride also accomplishes the dehydration of amides, where amide acts as a nucleophile. The first step of the mechanism involves the nucleophilic attack by the amide on the thionyl chloride to form an intermediate. In the next step, the electron pairs...


