A nonavalent BODIPY with a multivalent arrangement of α-mannosides enables lectins recognition in fluorescence-based assays

We report here the use of Tris-BODIPY-OH as a scaffold for the multivalent display of sugar heads. A chloroacetyl thioether ligation reaction easily yields mannosylated BODIPYs, named Man9-BODIPY and (Man-TEG)9-BODIPY, which display nine mannose residues. Regardless of the linker length, both glycoBODIPYs provide an arrangement of mannose heads that allows for proper recognition by the carbohydrate binding domain of concanavalin A (ConA). Moreover, the interactions of Man9-BODIPY with relevant human lectins, i.e. dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) and langerin, were further investigated. The approach proposed is versatile and paves the way for the development of multivalent and fluorescent glyco-BODIPY probes useful to interrogate carbohydrate–lectin interactions in different biological contexts.