A Highly Practical Synthesis of Cyclodextrin-Based Glycoclusters Having Enhanced Affinity with Lectins

A simple and highly practical method for the synthesis of cyclodextrin-scaffolded glycoclusters recognized specifically by lectins is described. Nucleophilic displacement of iodide from heptakis 6-deoxy-6-iodo-β-cyclodextrin by unprotected sodium thiolates derived from 3-(3-thioacetyl propionamido)propyl glycosides proceeded smoothly in mild condition and gave novel per-glycosylated cyclodextrins (glycocyclodextrins, glycoCDs) having d-galactose, N-acetyl-d-glucosamine, lactose or N-acetyllactosamine residues in high yields (78–88%). It was demonstrated that all these per-glycosylated β-cyclodextrins showed amplified inhibitory effects on the erythrocytes agglutination induced by wheat germ (Triticum vulgaris) agglutinin (WGA) or Erythrina corallodendron lectin (ECorL).