We describe an ecofriendly two-step synthesis of glycoamphiphiles, capable of hierarchical self-assembly into supramolecular hydrogels, consisting of Knoevenagel condensation of barbituric acid derivatives with biobased carbohydrates (glucose and maltose) and selective H2O2-mediated oxidative hydroxylation of barbiturates in water. By modifying the molecular design of glycostructures and the hydrophilic/hydrophobic balance, various glyco-nanostructures (ribbons, tapes, vesicles, helices, fibers) have been created via supramolecular self-assembly. In addition, we found that a water-soluble glycoamphiphile underwent sol-to-gel phase transition upon the addition of α-glucosidase as a result of the hydrolysis of the non-reducing-end glucose in the maltose moiety.