Laboratory of Molecular Science and Engineering, Åbo Akademi University, 20500Turku, Finland.
Institute of Biocomputation & Physics of Complex Systems (BIFI), University of Zaragoza, 50009Zaragoza, Spain.
J Org Chem. 2022 Nov 4;87(21):14544-14554. doi: 10.1021/acs.joc.2c01956. Epub 2022 Oct 17.
It was recently demonstrated by us that acetyl groups in oligosaccharides can migrate not only within one saccharide unit but also between two different saccharide units. Kinetics of this phenomenon were previously investigated in both mannan model compounds and a naturally occurring polysaccharide. In addition to mannans, there are also several other naturally acetylated polysaccharides, such as xyloglucans and xylans. Both xyloglucans and xylans are some of the most common acetylated polysaccharides in nature, displaying important roles in the plant cells. Considering the various biological roles of natural polysaccharides, it could be hypothesized that the intramolecular migration of acetyl groups might also be associated with regulation of the biological activity of polysaccharides in nature. Consequently, a better understanding of the overall migration phenomenon across the glycosidic bonds could help to understand the potential role of such migrations in the context of the biological activity of polysaccharides. Here, we present a detailed investigation on acetyl group migration in the synthesized xylan and glucan trisaccharide model compounds by a combination of experimental and computational methods, showing that the migration between the saccharide units proceeds from a secondary hydroxyl group of one saccharide unit toward a primary hydroxyl group of the other unit.
最近我们已经证明，寡糖中的乙酰基不仅可以在一个糖单元内迁移，还可以在两个不同的糖单元之间迁移。此前，我们已经在甘露聚糖模型化合物和天然存在的多糖中研究了这种现象的动力学。除了甘露聚糖，还有其他几种天然乙酰化多糖，如木葡聚糖和木聚糖。木葡聚糖和木聚糖都是自然界中最常见的乙酰化多糖之一，在植物细胞中发挥着重要作用。鉴于天然多糖的各种生物学作用，可以假设乙酰基的分子内迁移也可能与多糖生物活性的调节有关。因此，更好地了解糖苷键上的整体迁移现象有助于理解这种迁移在多糖生物活性背景下的潜在作用。在这里，我们通过实验和计算方法的结合，对合成的木聚糖和葡聚糖三糖模型化合物中的乙酰基迁移进行了详细研究，结果表明，糖单元之间的迁移是从一个糖单元的仲羟基向另一个糖单元的伯羟基进行的。
