Chemical synthesis of N-linked glycans carrying both mannose-6-phosphate and GlcNAc-mannose-6-phosphate motifs

Mannose-6-phosphate (M6P) containing N-linked glycans are the essential targeting signals for hydrolases sorting in eukaryotic cells. To facilitate their structural and binding analyses, a highly efficient and convergent method has been developed to prepare complex N-linked glycans with well-defined M6P and N-acetylglucosamine (GlcNAc)-M6P motifs, a newly identified binding element for M6P receptors. The GlcNAc-M6P motif was stereoselectively installed at the late stage of the synthesis. Sequential deprotection of benzyl and acetate groups provided the fully deprotected N-glycans in excellent yield.