Synthesis, Antibacterial Activity Evaluation and Mechanism Exploration of Indole Derivatives Containing [1,2,4]Triazole Moiety

ABSTRACT Bacterial diseases have been devastating plant pathogens to crops. However, there are few efficient agents to control them. Thus, it is crucial to find novel agents to protect crops from pathogenic bacteria. Here, we designed and synthesized a total of 24 novel indole derivatives containing a [1,2,4]triazole moiety, and their structures were characterized by 1 H, 13 C NMR, and high‐resolution mass spectrometry. Antibacterial activity revealed compound J (EC 50 = 4.31 ± 0.26 μg/mL) exhibited excellent activity in vitro against Xanthomonas oryzae pv. oryzae ( Xoo ) compared with the positive agent bismerthiazol (EC 50 = 40.23 ± 1.20 μg/mL) and thiodiazole‐copper (EC 50 = 34.85 ± 1.72 μg/mL). J (control efficiency was 56.96%) also showed good protective activity in vivo against Xoo compared with the positive agent 1‐phenazinecarboxylic acid (control efficiency was 37.01%). The preliminary mechanism showed J can inhibit Xoo through activating the ROS production, interfering with extracellular polysaccharide production, and biofilm formation of bacteria. On the other hand, J can increase the plant immunity reactions to hamper Xoo spread in the rice plant. The molecular docking of the most active compound J indicated excellent binding potential with its respective targets. These results demonstrated that J had a promising perspective and development as a potential antibacterial lead structure and agent in the future.