美国波士顿大学Niu Jia团队报道了脱水糖酐活性聚合中的精确天然多糖。相关研究成果发表在2023年4月27日出版的国际学术期刊《自然—化学》。

多糖的组成、序列、长度和糖苷键类型对其生物学和物理性质有着深刻的影响。然而，由于难以获得足够数量的明确多糖，对多糖结构-功能关系的研究受到阻碍。

该文中，研究人员报道了一种通过1，6-脱水糖的活性阳离子开环聚合来制备具有天然糖苷键的精确多糖的化学方法。研究人员使用三氟化硼醚化物催化剂和糖基氟化物引发剂合成了具有可调分子量、低分散性和优异区域和立体选择性的明确定义的多糖。计算研究表明，反应通过单体α-加成到羰基碳烯中进行传播，并通过传播的羰基碳烯的可逆失活来控制，以形成糖基氟化物休眠物种。

该方法为多种生物相关的精确多糖提供了一种简单且可扩展的途径，包括D-葡聚糖、D-甘露聚糖和一种不寻常的L-葡聚糖。研究证明，精确多糖的催化解聚有效地再生了单体，表明它们作为一类具有定制的热性能和机械性能的化学可回收材料具有潜在的用途。

附：英文原文

Title: Precision native polysaccharides from living polymerization of anhydrosugars

Author: Wu, Lianqian, Zhou, Zefeng, Sathe, Devavrat, Zhou, Junfeng, Dym, Shoshana, Zhao, Zhensheng, Wang, Junpeng, Niu, Jia

Issue&Volume: 2023-04-27

Abstract: The composition, sequence, length and type of glycosidic linkage of polysaccharides profoundly affect their biological and physical properties. However, investigation of the structure–function relationship of polysaccharides is hampered by difficulties in accessing well-defined polysaccharides in sufficient quantities. Here we report a chemical approach to precision polysaccharides with native glycosidic linkages via living cationic ring-opening polymerization of 1,6-anhydrosugars. We synthesized well-defined polysaccharides with tunable molecular weight, low dispersity and excellent regio- and stereo-selectivity using a boron trifluoride etherate catalyst and glycosyl fluoride initiators. Computational studies revealed that the reaction propagated through the monomer α-addition to the oxocarbenium and was controlled by the reversible deactivation of the propagating oxocarbenium to form the glycosyl fluoride dormant species. Our method afforded a facile and scalable pathway to multiple biologically relevant precision polysaccharides, including D-glucan, D-mannan and an unusual L-glucan. We demonstrated that catalytic depolymerization of precision polysaccharides efficiently regenerated monomers, suggesting their potential utility as a class of chemically recyclable materials with tailored thermal and mechanical properties.

DOI: 10.1038/s41557-023-01193-2

Source: https://www.nature.com/articles/s41557-023-01193-2