Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, VA 23529, USA.
Beilstein J Org Chem. 2014 Dec 23;10:3111-21. doi: 10.3762/bjoc.10.328. eCollection 2014.
Small molecular gelators are a class of compounds with potential applications for soft biomaterials. Low molecular weight hydrogelators are especially useful for exploring biomedical applications. Previously, we found that 4,6-O-benzylidene acetal protected D-glucose and D-glucosamine are well-suited as building blocks for the construction of low molecular weight gelators. To better understand the scope of D-glucosamine derivatives as gelators, we synthesized and screened a novel class of N-acetylglucosamine derivatives with a p-methoxybenzylidene acetal protective group. This modification did not exert a negative influence on the gelation. On the contrary, it actually enhanced the gelation tendency for many derivatives. The introduction of the additional methoxy group on the phenyl ring led to low molecular weight gelators with a higher pH responsiveness. The resulting gels were stable at neutral pH values but degraded in an acidic environment. The release profiles of naproxen from the pH responsive gels were also analyzed under acidic and neutral conditions. Our findings are useful for the design of novel triggered release self-assembling systems and can provide an insight into the influence of the the structure on gelation.
小分子凝胶剂是一类具有潜在应用的软生物材料化合物。低分子量水凝胶剂特别适用于探索生物医学应用。此前，我们发现 4,6-O-苄叉缩醛保护的 D-葡萄糖和 D-葡糖胺是构建低分子量凝胶剂的理想构建块。为了更好地了解 D-葡糖胺衍生物作为凝胶剂的范围，我们合成并筛选了一类具有对甲氧基苄叉缩醛保护基的新型 N-乙酰葡糖胺衍生物。这种修饰并没有对凝胶化产生负面影响。相反，它实际上增强了许多衍生物的凝胶化倾向。苯环上引入额外的甲氧基导致低分子量凝胶剂对 pH 值具有更高的响应性。所得凝胶在中性 pH 值下稳定，但在酸性环境中降解。还分析了萘普生在 pH 响应性凝胶中的释放情况，分别在酸性和中性条件下。我们的发现有助于设计新型触发释放自组装系统，并深入了解结构对凝胶化的影响。
