Biological activity evaluation and action mechanism of 1,4-Pentadien-3-one derivatives containing thiophene sulfonate

A series of novel 1,4-pentadien-3-one derivatives containing a thiophene sulfonate group were designed, synthesized, and their antibacterial activities were assessed. Antibacterial bioassays indicated that some of the title compounds exerted significant bioactivities against Xanthomonas axonopodis pv. Citri (Xac), Ralstonia solanacearum (Rs) and Xanthomonas oryzae pv. Oryzae (Xoo). Especially for Xac, the value of minimum 50% effective concentration (EC50) of compound 4-((1E,4E)-5-(3-nitrophenyl)-3-oxopenta-1,4-dien-1-yl)phenylthiophene-2-sulfonate (3k) is 11.0 μg/mL, which is significantly superior to bismerthiazol (BT) (51.6 µg/mL) and thiodiazole-copper (TC) (94.7 µg/mL). Meanwhile, the mechanism of action of compound 3k was confirmed by using scanning electron microscopy (SEM). These results suggested that 1,4-pentadien-3-one derivatives containing thiophene sulfonate group may be considered as activators in the design of antibacterial agents.