Design, synthesis and antibacterial activity study of an amide-coumarin derivatives

A series of amide-coumarin derivatives ( M1 – M20 ) were synthesized and evaluated for antibacterial activity against Xanthomonas oryzae pv. oryzicola (Xoc) , Xanthomonas campestris pv. citri (Xac) and Pseudomonas syringae pv. actinidiae (Psa) . Although all compounds showed moderate activity, M13 exhibited the strongest inhibition against Xoc with a half-maximal effective concentration of 59.3 mg/L, outperforming the controls thiodiazole copper and zinc thiazole. Density functional theory and electrostatic potential analyses were performed to elucidate the electronic structures. Molecular docking indicated that the amino group of M13 acts as a hydrogen-bond donor, interacting with residues LEU372 and GLU77. Furthermore, morphological changes in Xoc cells treated with M13 were observed using scanning electron microscopy.