Tris-bipyridine ruthenium complex-based glyco-clusters: amplified luminescence and enhanced lectin affinities

Tris-bipyridine ruthenium complexes carrying hexavalent α-glucoside, α-mannoside, and β-galactoside clusters were synthesized. Isomeric Λ- and Δ-complexes were separated, and their optical and conformational characteristics were investigated by UV–vis, CD, luminescence, and NMR spectroscopies as well as molecular dynamics calculation. The complexes exhibited strong luminescence and also strong inhibition of lectin-induced hemagglutination: particularly, the binding of hexavalent mannose cluster complexes to concanavalin A was strong.