Sulfone derivatives containing an oxazole moiety as potential antibacterial agents: design, synthesis, antibacterial activity, and mechanism.

Abstract

Bacterial diseases in plants pose a serious threat to crop production, leading to substantial food loss every year. Prolonged and repeated use of a single antibacterial agent can promote resistance in pathogenic bacteria. Therefore, there is an urgent need to develop efficient antibacterial agents for the treatment of bacterial diseases. Sulfone derivatives containing an oxazole moiety were designed and synthesized. Subsequently, their biological activities were evaluated. The half-maximal effective concentration (EC50) value of compound F10 against Xanthomonas oryzae pv. oryzicola (Xoc) was 1.1 mg/L, which was higher than those of commercial antibacterial agents, thiodiazole-copper (91.5 mg/L) and bismerthiazol (76.0 mg/L). The curative and protective effects of compound F10 against bacterial leaf streak in rice were 43.8% and 48.4%, respectively, at 200 mg/L, which were significantly superior to those of thiodiazole-copper (25.0% and 25.8%, respectively) and bismerthiazol (31.3% and 38.7%, respectively). Compound F10 inhibits Xoc by increasing the permeability of the cell membrane, inhibiting the production of extracellular polysaccharides, and affecting flagellar movement on the cell membrane. In addition, F10 reduces the pathogenicity of pathogenic bacteria, induces the accumulation of reactive oxygen species (ROS) in pathogenic bacteria, and produces adverse reactions. Compound F10 weakens bacterial pathogenicity by affecting the signal transduction of plant hormones, programmed cell death, and enhancing the ability to resist infection through the autoimmune response of rice. Therefore, compound F10 can be used as a potential antibacterial agent in future applications. © 2024 Society of Chemical Industry.