Design and Synthesis of Novel Trifluoromethylpyrimidinamine Derivatives Bearing an Amide Moiety for Targeting Plant Pathogens

Abstract

A series of novel trifluoromethylpyrimidinamine derivatives containing an amide moiety were designed and synthesized. The antimicrobial activity of the title compounds against various plant-pathogenic fungi and bacteria was evaluated. Among them, the EC50 of compound 7i against Pseudomonas syringae pv actinidiae (Psa) was 11.38 μg/mL, which was superior to that of the positive control thiodiazole copper (TC, 85.69 μg/mL), indicating excellent inhibitory activity. In vivo anti-Psa activity assays revealed that at 200 μg/mL, compound 7i conferred protective and curative effects of 69.10% and 65.16% on kiwifruit leaves, respectively, both of which were superior to those of TC (40.77% and 54.47%). Further mechanistic studies demonstrated that compound 7i disrupts cell integrity, induces leakage of intracellular proteins and nucleic acids, reduces extracellular polysaccharide production, and promotes the generation of reactive oxygen species. Additionally, molecular docking simulations of compound 7i with the FtsZ protein further confirmed its superior activity. The potent antibacterial activity of compound 7i supports its potential application in the prevention and control of plant disease.