Synthesis of Sugar Arrays in Microtiter Plate

1,3-Dipolar cycloadditions between azides and alkynes were exploited to attach oligosaccharides to a C14 hydrocarbon chain that noncovalently binds to the microtiter well surface. Synthesis of sugar arrays was performed on a micromolar scale in situ in the microtiter plate. As a model study, the β-galactosyllipid 5 was displayed on a 4-μmol scale. Formation of product was confirmed via ESI−MS, and the yield was determined via chemical and biological assays. Several complex carbohydrates (6−16) were also displayed in microtiter plates and successfully screened with various lectins. Moreover, sialyl Lewis x (17) was synthesized via the enzymatic fucosylation of a precursor displayed in the plate. Studies on inhibition of this biotransformation have been carried out, and the IC50 value found for the known inhibitor 20 was consistent with previous studies in solution.