Carbohydrate globules: molecular asterisk-cored dendrimers for carbohydrate presentation

Abstract

A convergent synthesis of a first generation dendrimer with biphenyl-based dendrons and a hexaphenylbenzene core is reported. Suzuki coupling of six first generation biphenyl-dendrons with the rigid hexakis(4-iodophenyl)benzene core furnished the title asterisk-cored dendrimer in 60% yield. Twelve copies of β-(1→6)-linked glucosamine-based oligosaccharides were then efficiently coupled with the acetylenyl surface groups of the dendrimer via a Huisgen 1,3-dipolar cycloaddition reaction to give a series of multivalent carbohydrate constructs that mimic the globular nodules of polysaccharide intercellular adhesin (PIA) produced by Staphylococcus aureus.