Tosylated and azidated inulins as key substrates for further chemical modifications to access inulin-based advanced materials: An inulin-based glycocluster

We successfully synthesized inulin tosylates by treating commercially available inulin with tosyl chloride and triethylamine in N,N-dimethylacetoamide at the ambient temperature for 24 h. The subsequent SN2 reactions using sodium azide afford inulin azides that can act as useful substrates for the following Huisgen cycloaddition with alkyne-terminated β-lactoside. The resultant inulin derivative having multiple β-lactosides has excellent affinity towards a β-lactoside binding lectin (RCA120). This synthetic strategy has various advantages, such as non-fragmentation of the inulin mainchain and wide applications for various alkyne-terminated functional units. Our strategy can be, therefore, used to develop various inulin derivatives that are applicable for food and medicinal industries.