Preparation of biotinylated allosamidins with strong chitinase inhibitory activities.

NaIO4 oxidation of allosamidin (1), a strong inhibitor of family 18 chitinases, followed by a coupling with Biotin Hydrazide 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.