Efficient Synthesis of Oligosaccharides and Glycopeptides by a Chemoenzymatic Strategy

Abstract

In the first part of this review, a new and efficient strategy for the synthesis of the sugar chains of glycoproteins is described. For the synthesis of N-linked sugar chains, the core-trisaccharide was synthesized by a chemical method with the aid of lipase. The side chain oligosaccharides were obtained enzymatically, using glycosidases, and the branched oligosaccharide blocks were obtained by regioselective chemical synthesis. Finally, the synthesized core-trisaccharide and side chain oligosaccharide blocks were combined to obtain N-linked sugar chains of arbitral structures.In the second part of this review, stepwise elongation of sugar chains employing exo-glycosidases to construct O-linked glycopeptides from GalNAc-linked peptides is described. Moreover, one-step syntheses using endo GlcNAc'ase or endo GalNAc'ase were performed for the construction of N-linked or O-linked glycopeptides, respectively. Several examples of the synthesis of glycopeptides are given.