Synthesis of Hexp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH2)7CH3 probes for exploration of the substrate specificity of glycosyltransferases

Article abstract of DOI:10.1016/S0008-6215(96)00266-2

Seven analogues of the trisaccharide β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃ have been synthesized as potential substrates for glycosyltransferases involved in the chain-termination of N-acetyllactosamine-type N-glycans. These compounds include: 3-O-methyl-β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, 3-deoxy-β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, 3 -deoxy-3-fluoro-β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, 3-amino-3-deoxy-β-D-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, β-D-Gulp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, β-L-Galp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃, and α-L-Altp-(1 → 4)-β-D-GlcpNAc-(1 → 2)-α-D-Manp-(1 → O)(CH₂)₇CH₃. All trisaccharides were obtained by condensation of suitably modified glycosyl donors based on imidates or thioglycosides with the same disaccharide acceptor, octyl 3,4,6-tri-O-benzyl-2-O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido- β-D -glucopyranosyl)-α-D-mannopyranoside, followed by deprotection.