Design, Synthesis, and Evaluation of Fungicidal Activity of Novel Pyrazole‐Containing Strobilurin Derivatives†

Abstract

Main observation and conclusionIn searching for novel fungicidal leads, a series of pyrazole‐containing strobilurins were rationally designed, synthesized and characterized. Bioassay indicated that compound I‐7 displayed excellent fungicidal activity against a broad spectrum of plant pathogens such as Gibberella zeae, Rhizoctonia cerealis, Sclerotinia sclerotiorum, Phytophthora infestans, Physalospora piricola and Pellicularia sasakii with EC50 of 0.16, 0.02, 0.72, 0.07, 0.77 and 0.65 μg/mL, respectively, which were 3—10 times more potent than the positive control azoxystrobin against the corresponding pathogens. Moreover, like azoxystrobin and kresoxim methyl, I‐7, displayed excellent protective activity against P. sorghi. Molecular docking validated that I‐7 and azoxystrobin would share a similar binding mode with cytochrome bc1 complex. This study demonstrates that I‐7 is a promising fungicidal candidate for further development.