Wang Dan, Chen Anji, Morris Joedian, Wang Guijun
Department of Chemistry and Biochemistry, Old Dominion University 4541 Hampton Boulevard Norfolk VA 23529-0126 USA
RSC Adv. 2020 Nov 4;10(66):40068-40083. doi: 10.1039/d0ra07587f. eCollection 2020 Nov 2.
Carbohydrate-based low molecular weight gelators (LMWGs) are interesting compounds with a variety of applications. In this research, a library of nineteen carbamate derivatives of -acetyl-d-glucosamine were synthesized and characterized, and several derivatives were found to be effective LMWGs. They formed gels in pump oils as well as mixtures of water with ethanol or water with DMSO. The structures of the carbamoyl chains played an important role in the gelation properties, short chain aliphatic derivatives and phenyl carbamates formed gels in more solvents than certain aromatic and dimeric carbamates. The phenyl carbamate gelator was also selected for the encapsulation of naproxen sodium, and the drug slowly diffused from the gel to the aqueous phase as indicated by UV-vis spectroscopy. In addition, we also found that the -methoxyl benzyl carbamate derivative showed interesting stimuli-responsive gelation properties in the presence of metal salts and tetrabutylammonium salts. The gels were characterized using optical microscopy, scanning electron microscopy, rheology and other methods. The self-assembling mechanisms of the gelators were studied using H NMR spectroscopy. The preparation, characterization, and molecular assembling properties of these compounds are reported. The results obtained from this study are useful for the design of other LMWGs and the sugar derivatives can be explored for different biological applications. The formation of spontaneous ionic gels can be applicable for a plethora of applications including catalysis and environmental remediation.
基于碳水化合物的低分子量凝胶剂（LMWGs）是一类具有多种应用的有趣化合物。在本研究中，合成并表征了19种α-乙酰基-d-葡萄糖胺的氨基甲酸酯衍生物库，发现其中几种衍生物是有效的LMWGs。它们能在泵油以及水与乙醇的混合物或水与二甲基亚砜的混合物中形成凝胶。氨基甲酰链的结构在凝胶化性能中起重要作用，短链脂肪族衍生物和苯基氨基甲酸酯比某些芳香族和二聚体氨基甲酸酯能在更多溶剂中形成凝胶。还选择了苯基氨基甲酸酯凝胶剂用于包封萘普生钠，紫外-可见光谱表明药物从凝胶中缓慢扩散到水相中。此外，我们还发现α-甲氧基苄基氨基甲酸酯衍生物在金属盐和四丁基铵盐存在下表现出有趣的刺激响应凝胶化性能。使用光学显微镜、扫描电子显微镜、流变学和其他方法对凝胶进行了表征。利用核磁共振氢谱研究了凝胶剂的自组装机制。报道了这些化合物的制备、表征和分子组装性能。本研究获得的结果有助于设计其他LMWGs，并且可以探索糖衍生物用于不同的生物应用。自发离子凝胶的形成可适用于包括催化和环境修复在内的大量应用。
