Preparation of biotinylated allosamidins with strong chitinase inhibitory activities

NaIO4 oxidation of allosamidin (1), a strong inhibitor of family 18 chitinases, followed, followed by a coupling with Biotin HydrazideR afforded its mono- and dibiotinylated derivatives, 4 and 6. Reduction of 4 by NaBH4 afforded its reduced form 5. Each of these three biotinylated derivatives maintained strong chitinase inhibitory activity. Especially, 6 inhibited a Trichoderma chitinase as strongly as 1.