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

We report here on the use of the Tris-BODIPY-OH as a scaffold for the multivalent display of sugar heads. A chloroacetyl thioether ligation reaction easily yields to mannosylated BODIPYs, named Man9-BODIPY and (Man-TEG)9-BODIPY, which display nine mannose residues. Regardless of 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.