Synthesis and antibacterial activities of 3-aryl-4-coumarinoxy phenylthiourea derivatives

In order to find thiourea derivatives containing coumarin moiety with high antibacterial activities, thirteen 3-aryl-4-coumarinoxy phenylthiourea derivatives were synthesized. Their structures were characterized by IR, ¹H NMR, ¹³C NMR, MS and elemental analysis, and their antibacterial activities against two pathogenic bacteria were preliminarily evaluated in this work. The results indicated that target compounds possessed good antibacterial activities. Among of them, compounds 4b , 4h , 4i , 4j and 4m showed excellent antibacterial activities against Xanthomonas oryzae pv. oryzae with EC₅₀ value of 117.7, 118.1, 105.7, 104.3 110.5 μg/mL, respectively, which were all superior to that of thiodiazole-copper (EC₅₀ value 195.8 μg/mL). Meanwhile, compounds 4b , 4h , 4i , 4j and 4m showed better antibacterial activities against Xanthomonas citri subsp. citri with EC₅₀ value of 111.6, 95.6, 102.9, 83.1, 112.1 μg/mL, respectively, which were superior to that of thiodiazole-copper (EC₅₀ value 128.7 μg/mL).