Glycans are exceptionally diverse and complex that deciphering the functions embedded within the glycome is a substantial challenge. The multiple regio- and stereochemical permutations for linking several monosaccharide units and the modifications that may follow chain assembly allowed these complex sugars to hold structural information densities that surpass DNA or proteins. With biosynthetic pathways that are regulated rather than template-driven, the sugars are usually expressed as an array of related structures that may possess subtle differences in activity. Several biological processes involve glycans, yet understanding their ligand specificities is impeded by their inherent diversity and difficult acquisition. Generating synthetic sugar libraries for bioevaluations forms the core of chemoglycomics approaches to unravel glycan structural information. A combination of “regioselective one-pot protection” and “stereoselective one-pot glycosylation” strategies to prepare a variety of cell-surface carbohydrates will be presented. Affinity screening and further X-ray co-crystal analysis of these synthesized sugars with proteins involving in infectious diseases to provide key insightsat the molecular level will be also highlighted.
