Design, synthesis, X-ray crystal structure and antibacterial activity of ferulic acid derivatives bearing sulfonamide moiety

A total of 28 new ferulic acid derivatives bearing the sulfonamide moiety were designed and synthesized, followed by an evaluation of their antibacterial activities. The structures of the synthesized compounds (<b>B1 − B28</b>) were fully characterized using ¹H NMR,¹³C NMR, and HRMS techniques. Among them, the structure of compound <b>B11</b> was further elucidated through X-ray single-crystal diffraction analyses. Bioassay results indicated that several target compounds exhibited significant inhibitory activity against the tested plant pathogens <i>in vitro</i>. Notably, compound <b>B28</b> demonstrated the highest resistance to <i>Xanthomonas oryzae</i> pv. <i>oryzicola</i> (<i>Xoc</i>), with an EC₅₀ (half-maximal effective concentration) value of 28.6 <i>μ</i>g/mL, which was more than twice as effective as the control agents zinc thiazole (EC₅₀ = 74.4 <i>μ</i>g/mL) and thiodiazole copper (EC₅₀ = 97.1 <i>μ</i>g/mL). Mechanistic studies revealed that <b>B28</b> enhances bacterial membrane permeability and disrupts cell morphology. This work highlights promising candidates for agricultural antibacterial applications.