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

In searching for novel fungicidal leads,a series of pyrazole-containing strobilurins were rationally designed,synthesized and charac-terized.Bioassay indicated that compound 1-7 displayed excellent fungicidal activity against a broad spectrum of plant pathogens such as Gibberella zeae,Rhizoctonia cereolis,Sclerotinia sclerotiorum,Phytophthora infestans,Physolosporo piricola and Pellicularia sosakii with EC_(50) of 0.16,0.02,0.72,0.07,0.77 and 0.65μg/mL,respectively,which were 3-10 times more potent than the positive control azoxystrobin against the corresponding pathogens.Moreover,like azoxystrobin and kresoxim methyl,1-7,displayed excellent protec-tive activity against P.sorghi.Molecular docking validated that 1-7 and azoxystrobin would share a similar binding mode with cytochrome bc_(1) complex.This study demonstrates that 1-7 is a promising fungicidal candidate for further development.