Synthesis, Bioactivities, and Antibacterial Mechanism of 5-(Thioether)--phenyl/benzyl-1,3,4-oxadiazole-2-carboxamide/amine Derivatives.

1,3,4-Oxadiazole thioethers have shown exciting antibacterial activities; however, the current mechanism of action involving such substances against bacteria is limited to proteomics-mediated protein pathways and differentially expressed gene analysis. Herein, we report a series of novel 1,3,4-oxadiazole thioethers containing a carboxamide/amine moiety, most of which show good and bacteriostatic activities. Compounds and were screened through CoMFA models as optimums against pv. (, EC values of 5.32 and 4.63 mg/L, respectively) and pv. (, EC values of 7.58 and 7.65 mg/L, respectively). Compound was implemented in proteomic techniques and activity-based protein profiling (ABPP) analysis to elucidate the antibacterial mechanism and biochemical targets. The results indicate that disrupts the growth and pathogenicity of by interfering with pathways associated with bacterial virulence, including the two-component regulation system, flagellar assembly, bacterial secretion system, quorum sensing, ABC transporters, and bacterial chemotaxis. Specifically, the translational regulator (CsrA) and the virulence regulator (Xoc3530) are two effective target proteins of . Knocking out the or gene in results in a significant reduction in the motility and pathogenicity of the mutant strains. This study contributes available molecular entities, effective targets, and mechanism basis for the management of rice bacterial diseases.