Cai Lei, Chen Qi, Guo Jian, Liang Zhihua, Fu Dengxian, Meng Lingkui, Zeng Jing, Wan Qian
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Huazhong University of Science and Technology 13 Hangkong Road Wuhan Hubei 430030 China
Chem Sci. 2022 Jun 22;13(30):8759-8765. doi: 10.1039/d2sc01700h. eCollection 2022 Aug 4.
Herein, we report a novel fluorous-tag assisted two-directional oligosaccharide assembly strategy, which maintained the high coupling efficiency of solution-phase synthesis and featured the advantage of an easy purification process comparable to solid-phase synthesis. A well-designed fluorous tag was decorated on the latent anomeric leaving group in interrupted Pummerer reaction mediated (IPRm) glycosylation. The high efficiency of the in-solution phase glycosylation and the unique affinity of the fluorous tag towards polytetrafluoroethylene (PTFE) particles allowed flexible assembly from the reducing end to the non-reducing end and fast purification by PTFE-assisted filtration. Moreover, the fluorous-tagged latent anomeric leaving group could be activated by oxidation and cleaved by IPRm glycosylation, thus enabling the elongation of the carbohydrate chain from the non-reducing end to the reducing end as well as the recovery of the fluorous tag. The present two-directional synthetic strategy is used to assemble the repeating unit of type 14 capsular polysaccharide.
在此，我们报道了一种新型的氟标签辅助双向寡糖组装策略，该策略保持了溶液相合成的高偶联效率，并具有与固相合成相当的易于纯化的优点。在中断的普默勒反应介导（IPRm）的糖基化中，一个精心设计的氟标签被修饰在潜在的异头离去基团上。溶液相糖基化的高效率以及氟标签对聚四氟乙烯（PTFE）颗粒的独特亲和力使得能够从还原端到非还原端进行灵活组装，并通过PTFE辅助过滤进行快速纯化。此外，带有氟标签的潜在异头离去基团可以通过氧化激活并通过IPRm糖基化裂解，从而实现碳水化合物链从非还原端到还原端的延长以及氟标签的回收。目前的双向合成策略用于组装14型荚膜多糖的重复单元。
