Role of Protecting Groups in Synthesis and Self-Assembly of Glycopolymers.
Role of Protecting Groups in Synthesis and Self-Assembly of Glycopolymers.
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DOI：
10.1021/acs.biomac.6b01716
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发表时间：
2017-01
影响因子：
6.2
通讯作者：
Yu Zhao;Yufei Zhang;Changchun Wang;Guosong Chen;Ming Jiang
中科院分区：
文献类型：
--
作者：
Yu Zhao;Yufei Zhang;Changchun Wang;Guosong Chen;Ming Jiang
保护和去保护是低聚糖合成的基本步骤。通过利用连接和去除保护基团的方法，可以以相对较高的产率制备具有复杂结构的寡糖。然而，文献中忽略了保护基团在合成糖共聚物的溶液性质和自组装中的作用。在这篇论文中，我们重点研究了糖环上不同数目的苄基(Bn)区域选择性地安装在设计良好的共聚物中的这种效应。因此，制备了三种嵌段共聚物P1、P2和P3，所述嵌段共聚物由公共的PNIPAM嵌段和具有不同数目的Bn(0、2和6)的三糖Triman侧链的糖共聚物组成。用动态和静态光散射和VT-1H核磁共振研究了这些嵌段共聚物的水溶液。我们发现，三种共聚物P1、P2和P3在室温下都形成了缔合。特别是，P1由于碳水化合物-碳水化合物相互作用(CCI)而松散结合，而P3由于Bn之间的疏水作用而形成紧密的聚集体，P2表现在P1和P3之间。此外，PNIPAM嵌段在受热时发生相变，形成胶束。P1和P2的流体动力学半径如预期的那样显著增大，而P3则没有遵循这一趋势，这是因为在加热过程中，PNIPAM链的坍塌和积累主要发生在紧密的聚集体中，因此导致尺寸略有变化。
Protection and deprotection are basic procedures in oligosaccharide synthesis. By taking advantage of the processes of attaching and removing the protecting groups, preparation of oligosaccharides with complex structures can be achieved with relatively high yields. However, the role of protecting groups in solution properties and self-assembly of synthetic glycopolymers has been overlooked in the literature. In this paper, we focused on such effects for well-designed copolymers in which different numbers of benzyl (Bn) groups are installed regioselectively in saccharide rings. Thus, three block copolymers P1, P2, and P3 composed of a common block of PNIPAm and a glycopolymer block with trisaccharide triMan side chains differing in the respective number of Bn (0, 2, and 6) were prepared. The solutions of these block copolymers in water were investigated by dynamic and static light scatting and VT-1H NMR. We found that all of the three copolymers P1, P2, and P3 formed association at room temperature. Particularly, P1 associated loosely due to carbohydrate-carbohydrate interaction (CCI) while P3 formed tight aggregates due to hydrophobic interactions between Bn, and P2 behaved between those of P1 and P3. Moreover, upon heating, phase transition of PNIPAm block took place leading to micelle formation. Hydrodynamic radius of P1 and P2 increased significantly as expected, while P3 did not follow this trend, because during heating, collapse and accumulation of the PNIPAm chains would occur within the tight aggregates mainly, so it leads to a little change of the size.