Antibacterial Activity Evaluation

The antibacterial activities were evaluated by the conventional broth dilution assay [45 (link)]. Five phytopathogenic bacteria (Xanthomonas citri pv. malvacearum, X. axonopodis, Comamonas terrigena, Pseudomonas syringae, and Dickeya chrysanthemi), four animal pathogenic bacteria (Escherichia coli, P. aeruginosa, Staphylococcus aureus, and Bacillus subtilis), and eight marine fouling bacteria (Aeromonas hydrophila, A. salmonicida, Enterobacter cloacae, P. fulva, Vibrio anguillarum, V. harveyi, Photobacterium halotolerans, and P. angustum) were used, and cipofloxacin (CPFX) and DMSO were used as the positive and negative control, respectively. The antibacterial activity assay was carried out by using previously described methods [22 (link),23 (link)]. The tested concentrations of isolated compounds and CPFX were 100 µM, 50 µM, 25 µM, 12.5 µM, 6.25 µM, 3.13 µM, 1.56 µM, 0.78 µM, 0.39 µM, and 100 µM, 50 µM, 25 µM, 12.5 µM, 6.25 µM, 3.13 µM, 1.56 µM, 0.78 µM, 0.39 µM, 0.20 µM, 0.10 µM, 0.049 µM, and 0.024 µM, respectively.