Synthesis and characterization of thiourea- and urea-linked glycolipids as low-molecular-weight hydrogelators

Abstract

Novel glycolipids with thiourea- and urea-linkers have been synthesized as low-molecular-weight gelators by reacting glycosyl aminoacetamides with alkyl isothiocyanates and isocyanates. The influence of the linker groups on their self-assembly properties has been studied. A gelation study of the obtained neoglycolipids in various solvents showed that they are good hydrogelators. Urea-linked glycolipids showed better hydrogelating ability as compared to thiourea linked glycolipids. The influence of sugar head group and alkyl chain length on the glycolipid’s self-assembly has also been studied. The fibrillar structures of the supramolecular hydrogels have been characterized by scanning electron microscopy (SEM). The thermal properties of the hydrogels formed by urea linked glycolipids have been studied by differential scanning calorimetry (DSC) and VT-NMR. Molecular packing has been studied by small angle (SAXS) and single crystal X-ray diffraction methods.