Synergistic effect of the hybrid compounds of cationic pillararene and an efflux pump inhibitor against Gram-negative bacteria†

Novel antibiofilm agents were designed by integrating cationic pillararene with an efflux pump inhibitor. The hybrid compounds were prepared and characterized using NMR and HRMS. These compounds exhibited potent activity to inhibit biofilm formation and disrupt the outer membrane in Gram-negative bacteria. In addition, the synergistic effect of the hybrid compounds was observed in combination with antibiotics, especially against P. aeruginosa. The hybridization strategy not only reduced the dosages required for the efflux pump inhibitor but also enhanced the antibacterial efficacy of antibiotics, making this a promising approach for developing antibacterial drugs.