Chemoenzymatic Synthesis of Triazole-Linked Glycopeptides

Abstract

Triazole-linked glycopeptides are prepared by C-terminal elongation of glycoamino acids with proteinogenic amino acids following a chemical or enzymatic coupling protocol. Two orthogonal routes for a chemoenzymatic strategy were explored, involving a click-reaction before amide bond formation or in reverse order. It was found that enzymatic peptide coupling under the influence of alcalase proceeds cleanly and in high yields, while the resulting dipeptides can be efficiently clicked to acetylene- or azide-containing sugars.