Chemical synthesis of the Pseudomonas aeruginosa O11 O-antigen trisaccharide based on neighboring electron-donating effect
Chemical synthesis of the Pseudomonas aeruginosa O11 O-antigen trisaccharide based on neighboring electron-donating effect
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基于邻近给电子效应的铜绿假单胞菌O11 O抗原三糖的化学合成
DOI：
10.1080/07328303.2020.1839479
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发表时间：
2020
影响因子：
1
通讯作者：
Jian Yin
中科院分区：
文献类型：
--
作者：
Chunjun Qin;Zhonghua Liu;Meiru Ding;Juntao Cai;Junjie Fu;Jing Hu;Peter H. Seeberger;Jian Yin
铜绿假单胞菌O_（11）O抗原具有免疫活性，但其确切的保护性表位尚未确定。O_（11）O抗原三糖的合成对确定O_（11）O抗原表位具有重要意义。在这里，相邻的给电子效应是增强D-和L-岩藻糖胺的C3羟基的亲核性以促进三糖的有效合成的关键。具有低糖基化反应性的解除武装的全乙酰化糖基供体和具有良好稳定性的糖基三氟乙酰亚胺酯允许在温和条件下进行糖基化。发现碘对D-半乳糖的C6亲核甲苯磺酸酯取代依赖于轴向C4的空间效应。
Abstract Pseudomonas aeruginosa O11 O-antigen is immunologically active but an exact protective epitope has not yet been identified. Synthesis of O11 O-antigen trisaccharide is of importance for identifying the epitopes. Here, neighboring electron-donating effects are keys to enhance the nucleophilicity of the C3 hydroxyl groups of D- and L-fucosamines, to facilitate the efficient synthesis of the trisaccharide. The disarmed peracetylated glycosyl donor with low glycosylation reactivity and glycosyl trifluoroacetimidate with good stability allowed for the glycosylation under mild conditions. The C6 nucleophilic tosylate substitution of D-galactose with iodine was found to be dependent on the steric effect of the axial C4.