Synthesis of divalent α-D-mannopyranosylated clusters having enhanced binding affinities towards concanavalin A and pea lectins

Two different α-D-mannopyranosides having aminated heteroaliphatic (2) and p-isothiocyanatophenylated (10) aglycones were prepared and used as key precursors for the conjugation to a 3,5-diaminobenzoic acid core (3) using thiourea and amide coupling chemistry. The resulting divalent mannopyranoside clusters 6, 7, and 12 were shown to inhibit binding of Concanavalin A and pea lectins to yeast mannan more efficiently than their corresponding monosaccharide derivatives.