Novel Butenolide Derivatives as Dual-Chitinase Inhibitors to Arrest the Growth and Development of the Asian Corn Borer.

Of ChtI and Of Chi-h are considered potential targets for the control of Asian corn borer ( Ostrinia furnacalis ). In this work, the previously reported Of ChtI inhibitor 5f was found to show certain inhibitory activity against Of Chi-h ( K _i = 5.81 μM). Two series of novel butenolide derivatives based on lead compound 5f were designed with the conjugate skeleton, contributing to the π-binding interaction to chitinase, and then synthesized. Compounds 4a-l and 7a-p displayed excellent inhibitory activities against Of ChtI and Of Chi-h, respectively, at a concentration of 10 μM. Compound 4h was found to be a good dual-Chitinase inhibitor, with K _i values of 1.82 and 2.00 μM against Of ChtI and Of Chi-h, respectively. The inhibitory mechanism studies by molecular docking suggested that π-π stacking interactions were crucial to the inhibitory activity of novel butenolide derivatives against two different chitinases. A preliminary bioassay indicated that 4h exhibited certain growth inhibition effects against O. furnacalis . Butenolide-like analogues should be further studied as promising novel dual-chitinase inhibitor candidates for the control of O. furnacalis .