Chair for Biogenic Polymers, TUM Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, Straubing 94315, Germany.
Biomacromolecules. 2022 Jun 13;23(6):2280-2289. doi: 10.1021/acs.biomac.1c01673. Epub 2022 Jun 3.
All-glucose block copolysaccharides with alternated α- and β-configured blocks do not exist in nature. Such polysaccharides, and materials made thereof, might exhibit very interesting properties due to the different supramolecular structures of the two α- and β-configured blocks. This would be helical for starch and linear for cellulose in the case of a non-derivatized all-glucose polysaccharide. We propose a synthetic pathway for the preparation of methylated and acetylated building blocks of cellulose and amylose for the regioselective modification at the non-reducing and reducing end to act as glycosyl acceptors and donors, respectively. The glycosyl acceptors with the opposite α- or β-configured blocks were prepared by acid-catalyzed methanolysis of permethylated amylose as well as cellulose. The regioselectively modified glycosyl donors and acceptors were successfully used in the preparation of block copolysaccharides with an α(1 → 4)-configured and a β(1 → 4)-configured oligo- or polysaccharide block, respectively.
自然界中不存在全葡萄糖嵌段共聚物，其交替的α-和β-构型块。由于两种α-和β-构型块的超分子结构不同，这种多糖及其材料可能表现出非常有趣的性质。在未衍生的全葡萄糖多糖的情况下，淀粉是螺旋的，而纤维素是线性的。我们提出了一种合成路线，用于制备甲基化和乙酰化的纤维素和直链淀粉的构建块，以便在非还原端和还原端进行区域选择性修饰，分别作为糖基受体和供体。通过酸催化的甲醇解反应，从全甲基化的直链淀粉和纤维素中制备了具有相反α-或β-构型块的糖基受体。区域选择性修饰的糖基供体和受体成功地用于制备具有α(1 → 4)-构型和β(1 → 4)-构型低聚糖或多糖块的嵌段共聚物。
