Probe sialidase substrate specificity using chemoenzymatically synthesized sialosides containing C9-modified sialic acid

A library of α2–3- and α2–6-linked sialyl galactosides containing C9-modified sialic acids was synthesized from C6-modified mannose derivatives using an efficient one-pot three-enzyme system. These sialosides were used in a high-throughput sialidase substrate specificity assay to elucidate the importance of C9–OH in sialidase recognition.