隐身C的生产涉及S-N型微笑重新排列
Peng Wang1, Gloria J Hong1, Matthew R Wilson1
1Department of Chemistry & Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States.
Journal of the American Chemical Society
|February 14, 2017
概括
研究人员发现了一种单一的酶AlpJ,它负责产生胺和隐形C,这是胺生物合成中的关键化合物. 这一发现揭示了在天然产品中产生芳香氨基群的新途径.
科学领域:
- 自然产品生物合成
- 酶化学
- 聚化物合成
背景情况:
- 氨酸家族,芳香型多基,具有独特的氨酸环和氨酸组.
- 这些结构特征的生物合成途径在很大程度上仍未被描述.
研究的目的:
- 研究基因胺天然产品生物合成的酶机制.
- 为了阐明seongomycin和stealthin C的产生,相关的代谢物.
主要方法:
- 在体内和体外生产seongomycin和stealthin C.
- 使用黄素依赖单氧酶AlpJ的酶测试.
- 来自N-乙-l-氨酸和l-氨酸的反应产物的分析.
主要成果:
- 一个叫做AlpJ的酶从N-乙-l-氨酸中产生氨酸,从l-氨酸中产生隐形氨酸.
- 隐形C合成似乎涉及一个非酶的S-N型微笑重组.
- 这一途径是将芳香氨基基组引入代谢物的不寻常机制.
结论:
- 黄素依赖的单氧酶AlpJ在氨酸代谢途径的生物合成中起着至关重要的作用.
- 非酶的微笑重新排列为芳香氨基群安装提供了一种新途径.
- 需要进一步的研究来证实stealthin C在胺素生产中的中间作用.
相关概念视频
SN2 Reaction: Mechanism
18.0K
The kinetic studies of SN2 reactions suggest an essential feature of its mechanism: it is a single-step process without intermediates. Here, both the nucleophile and the substrate participate in the rate-determining step.
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
18.0K
SN2 Reaction: Stereochemistry
12.3K
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
12.3K
SN1 Reaction: Stereochemistry
10.8K
This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
10.8K
Thermal Sigmatropic Reactions: Overview
2.6K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred...
2.6K
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
3.5K
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
3.5K
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement
2.9K
The Claisen rearrangement is a [3,3] sigmatropic rearrangement of allyl vinyl ethers to unsaturated carbonyl compounds. The rearrangement is a concerted pericyclic reaction proceeding via a chair-like transition state.
2.9K


