Department of Wood Science and Forest Products, Macromolecules and Interfaces Institute, Virginia Tech, Blacksburg, Virginia 24061, United States.
Biomacromolecules. 2012 Apr 9;13(4):992-1001. doi: 10.1021/bm2017004. Epub 2012 Mar 7.
Aminated polysaccharides have been extensively investigated for a wide range of biomedical applications. To achieve targeted properties such as solubility and miscibility, it can be beneficial to modify the polysaccharide hydroxyl groups selectively while leaving the amino groups unmodified. This tends to be difficult because of the higher reactivity of primary amines than hydroxyl groups toward electrophilic reagents. We describe herein a new method that can produce O-acylated, aminated polysaccharides with extremely high selectivity. In this procedure, 6-azido-6-deoxy-cellulose esters are synthesized from 6-bromo-6-deoxy-cellulose esters. The azide groups are then selectively and mildly reduced using the Staudinger reaction to produce 6-amino-6-deoxy-2,3-di-O-acyl-cellulose derivatives. This demonstrates the effectiveness of the Staudinger reduction on a polysaccharide substrate in the presence of easily reducible ester groups.
已广泛研究了胺化多糖在广泛的生物医学应用中的作用。为了获得目标性质，例如溶解度和混溶性，可以通过选择性修饰多糖的羟基而不修饰氨基来实现。由于伯胺比羟基对亲电试剂的反应性更高，因此这往往很困难。我们在此描述了一种可以产生具有极高选择性的 O-酰化，胺化多糖的新方法。在该程序中，从 6-溴代-6-脱氧纤维素酯合成 6-叠氮基-6-脱氧纤维素酯。然后使用 Staudinger 反应温和地选择性还原叠氮基团，以生成 6-氨基-6-脱氧-2,3-二-O-酰基纤维素衍生物。这证明了 Staudinger 还原在存在易还原的酯基的多糖底物上的有效性。
