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.