Multivalent glycoclusters constructed by chiral self-assembly of mannose functionalized perylene bisimide

Water-soluble perylene bisimide derivative 7 modified with six mannoses was synthesized and its self-assembled properties were studied by UV-Vis and CD spectroscopy, which revealed an interesting self-assembly with a solvent-tuning chiral conformation in H2O-DMSO solution. As H2O was added to the DMSO solution until a 60% (or 70%) v/v proportion was achieved, the self-assembly of the mannose functionalized compound 7 exhibited a left-handed helical conformation. More interestingly, when the volume of H2O constituted beyond 85% of the solution, the conformation of the self-assembly turned out to be a right-handed helical conformation. Furthermore, the binding interactions between the self-assembly of compound 7 and Con A were investigated by turbidity assay, CD spectra, TEM and SEM images, and ELLA experiment, which indicated that the self-assembly of compound 7 as multivalent glycoclusters exhibited specific binding to Con A with an IC50 value of 24 mu M (144 mu M, valency corrected), 10 times stronger than the reference compound (alpha-MMP).