Differential Recognition of Mannose-Based Polysaccharides by Tripodal Receptors Based on a Triethylbenzene Scaffold Substituted with Trihydroxybenzoyl Moieties

The tripodal receptors 1 and 2 based on a triethylbenzene scaffold substituted with trihydroxybenzoyl groups have been synthesised. The conformational preferences and carbohydrate-binding ability of 1 and 2 have been examined by NMR spectroscopy and modelling procedures. The results reveal that the particular structural pre-organisation of 2 facilitates the recognition, in a highly competitive medium (DMSO), of a mannose-based polysaccharide consisting of a linear saccharide chain continuously decorated by alpha(1 -> 2)-linked branching mannose moieties. By contrast, other alpha(1 -> 2)-substituted polysaccharides or different monosaccharides are not bound, revealing the selectivity of the interaction. Due to the importance of alpha(1 -> 2) mannosides, which are abundantly present on the glycan shield of several pathogens, the results reported here open attractive prospects for the potential application of 2 or its derivatives in future antiinfective strategies.