Chemical synthesis of the N-glycans of gp63, the major surface glycoprotein from Leishmania mexicana amazonensis

Abstract

The chemical synthesis of the conjugated heptasaccharide Man(α1-3)Man(α1-6)[Glc(α1-3)Man(α1-2)Man(α1-2)Man(α1-3)]Manβ1-O[CH₂]₈CO₂Me 1 and four closely related biantennary oligomannose type structures derived from the glycoprotein 63 of Leishmania mexicana amazonensis is described. Taking advantage of common structural motifs found in these N-glycans, a strategy based on the principles of reactivity tuning and orthogonal activation allowed the rapid assembly of a whole class of complex oligosaccharides. Deprotection of all structures was achieved in high yields by hydrogenolysis in one step.