関連する実験動画
Updated: Jul 25, 2026
12:06
Metabolic Glycoengineering of Sialic Acid Using N-acyl-modified Mannosamines
Published on: November 25, 2017
オリゴ-アルファ-(2,8) -シアル酸のステレオ選択合成
Hiroshi Tanaka1, Yuji Nishiura, Takashi Takahashi
1Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology 2-12-1-S1-35, Oookayama, Meguro, Tokyo 152-8552, Japan. thiroshi@apc.titech.ac.jp
Journal of the American Chemical Society
|June 1, 2006
まとめ
この研究では,アルファ ((2,8) -オリゴシアロシドの効率的な合成が示されています. 新しい保護されたシアリルドナーにより,テトラアルファ2,8-シアル酸を含む複雑なオリゴシアロシドの高収量生産が可能になる.
科学分野:
- 炭水化物化学 炭水化物の化学
- オーガニック・シンセシス オーガニック・シンセシス
- グライコバイオロジーは,
背景:
- オリゴシアロシドは,生物学的プロセスにおいて重要な役割を果たします.
- アルファ ((2,8) 結合シアリック酸構造の効率的な合成は困難です.
- これらの構造を理解するには,信頼できる合成方法が必要です.
研究 の 目的:
- アルファ2,8-オリゴシアロシドの効率的かつエレガントな合成を開発する.
- 新しい保護されたシアリルドナーの有用性を調査する.
- テトラアルファ2,8-シアル酸を合成する.
主な方法:
- 5-N,4-O-カルボニルで保護されたシアリルドナーを用いた合成.
- ディクロロメタン (CH2Cl2) のアルファシアライレーション反応.
- グライコシデーションとデプロテクションプロトコル.
主要な成果:
- アルファ2,8およびアルファ2,9ジアロシドの優れた収量が得られた.
- 5-N,4-O-カルボニル保護群はC8ヒドロキシル群の反応性を高めました.
- テトラアルファ ((2,8) -シアル酸の合成が成功しました.
結論:
- 開発された方法は,アルファ2,8-オリゴシアロシドへの効率的な経路を提供します.
- 保護されたシアリルドナーはアルファシアリレーションに有効です.
- この合成により,オリゴシアロシドの生物学的機能に関するさらなる研究が容易になる.
関連する概念動画
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
02:23SN2 Reaction: Stereochemistry
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 observed.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
02:44Oxidation 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.
01:24Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.