科學家實現稀有糖異構體合成

科學家實現稀有糖異構體合成

作者：

小柯機器人

發布時間：2020/1/19 18:50:39

美國麻省理工學院Alison E. Wendlandt研究組近日取得一項新成果，他們通過位點選擇性差向異構合成了稀有的糖異構體。該研究於2020年1月15日在線發表於國際一流學術期刊《自然》。

研究人員報導了通過位點選擇性差向異構化反應直接從生物質碳水化合物製備稀有糖異構體。機理研究表明，這些反應是在動力學控制下進行的，即通過兩個不同的催化劑介導的氫原子提取和氫原子供體的順序步驟進行的。這種合成策略為此類有價值天然化合物提供了簡潔且可能廣泛的途徑。

據悉，聚糖具有多種生理功能，從能量存儲和結構完整性到細胞信號傳導和細胞內過程的調節。儘管源自生物質的碳水化合物（例如（D）-葡萄糖、（D）-木糖和（D）-半乳糖）能夠以商業規模提取，並用作可再生的化學原料和基石，但仍有數百種單糖通常無法從其天然來源中分離出來，而必須通過多步化學或酶促合成方法製備。這些「稀有」糖在具有生物活性的天然產物和藥物中具有顯著特徵，包括許多FDA批准的抗病毒、抗菌、抗癌和強心藥。

附：英文原文

Title: Synthesis of rare sugar isomers through site-selective epimerization

Author: Yong Wang, Hayden M. Carder, Alison E. Wendlandt

Issue&Volume: 2020-01-15

Abstract: Glycans have diverse physiological functions, ranging from energy storage and structural integrity to cell signalling and the regulation of intracellular processes1. Although biomass-derived carbohydrates (such as (D)-glucose, (D)-xylose and (D)-galactose) are extracted on commercial scales, and serve as renewable chemical feedstocks and building blocks2,3, there are many hundreds of distinct monosaccharides that typically cannot be isolated from their natural sources and must instead be prepared through multistep chemical or enzymatic syntheses4,5. These 『rare』 sugars feature prominently in bioactive natural products and pharmaceuticals, including many FDA-approved antiviral, antibacterial, anti-cancer and cardiac drugs6,7. Here we report the preparation of rare sugar isomers directly from biomass carbohydrates through site-selective epimerization reactions. Mechanistic studies establish that these reactions proceed under kinetic control, through sequential steps of hydrogen atom abstraction and hydrogen atom donation mediated by two distinct catalysts. This synthetic strategy provides concise and potentially extensive access to this valuable class of natural compounds.

DOI: 10.1038/s41586-020-1937-1

Source: https://www.nature.com/articles/s41586-020-1937-1