Automated High-Throughput Synthesis of Artificial Glycopeptides. Small-Molecule Probes for Chemical Glycobiology

A fully automated method for the synthesis of artificial glycopeptides having two (similar or different) carbon-linked glycosyl moieties on a dipeptide scaffold has been developed. By use of this approach that combines the diversity of peptide/pseudopeptide and glycosides, different glycoside moieties can be incorporated onto the peptide/pseudopeptide backbone in a highly controlled manner. The approach utilizes a stepwise reductive amination with glycoside aldehyde derivatives (model 1) or (ii) glycoside reductive amination followed by glycoside amide bond formation (model 2). Further, an automated method has been utilized in the high-throughput library synthesis of 4 x 96 artificial glycopeptides. These libraries were tested as chemical probes/inhibitors of enzyme systems that convert a glucose moiety into rhamnose prior to incorporation of the rhamnose unit and the conversion of UDP-galactopyranose to UDP-galactofuranose via UDP-galactopyranose mutase enzyme during the biosynthesis of the mycobacterium cell wall.