Discovery of Novel Inhibitors Targeting Fungal Chitin Deacetylase via Virtual Screening for Plant Disease Control

Fungal chitin deacetylase (CDA) plays a crucial role in pathogen–plant interactions, which is regarded as an innovative and promising target for fungicides. In this study, a pharmacophore-based virtual screening strategy was employed to identify compounds VS-24 and VS-25 as potent inhibitors against Puccinia striiformis f. sp. tritici CDA (PstCDA). Further bioassays demonstrated that VS-24 exhibited a protective effect of 61.2% against rice blast at 100 μg/mL, while VS-25 showed a superior protective effect of 45.5% against corn rust at 5 μg/mL, both superior to the reported CDA inhibitor benzohydroxamic acid (BHA). Molecular dynamics simulations revealed that multiple key interactions involving the Zn²⁺ ion and residues His207 and Tyr152 of PstCDA are critical for the binding of VS-24 or VS-25, with electrostatic interactions contributing most significantly to the binding free energy. Finally, toxicity predictions confirmed the potential biosafety of VS-24 and VS-25. Overall, this study identified two promising lead compounds targeting fungal CDA to control plant diseases.