Leiden University, Leiden Institute of Chemistry, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.
Angew Chem Int Ed Engl. 2021 Jan 11;60(2):937-945. doi: 10.1002/anie.202010280. Epub 2020 Nov 3.
The assembly of complex bacterial glycans presenting rare structural motifs and cis-glycosidic linkages is significantly obstructed by the lack of knowledge of the reactivity of the constituting building blocks and the stereoselectivity of the reactions in which they partake. We here report a strategy to map the reactivity of carbohydrate building blocks and apply it to understand the reactivity of the bacterial sugar, caryophyllose, a rare C12-monosaccharide, containing a characteristic tetrasubstituted stereocenter. We mapped reactivity-stereoselectivity relationships for caryophyllose donor and acceptor glycosides by a systematic series of glycosylations in combination with the detection and characterization of different reactive intermediates using experimental and computational techniques. The insights garnered from these studies enabled the rational design of building blocks with the required properties to assemble mycobacterial lipooligosaccharide fragments of M. marinum.
组装具有罕见结构基序和顺式糖苷键的复杂细菌聚糖，受到组成构建块的反应性和它们参与的反应的立体选择性知识的严重阻碍。我们在这里报告了一种绘制碳水化合物构建块反应性的策略，并将其应用于理解细菌糖，石蒜醇的反应性，这是一种罕见的 C12 单糖，含有一个特征的四取代立体中心。我们通过一系列糖苷化反应，并结合使用实验和计算技术检测和表征不同的反应中间体，绘制了石蒜醇供体和受体糖苷的反应性-立体选择性关系。从这些研究中获得的见解使我们能够合理设计具有所需性质的构建块，以组装分枝杆菌脂寡糖片段 M. marinum。
