Quorum sensing-IN-2 (compound 23e) is a quorum sensing inhibitor, which can reduce the pathogenicity of bacteria without affecting bacterial growth. Quorum sensing-IN-2 inhibits bacterial infections with little hemolytic activity. Quorum sensing-IN-2 shows synergistic effect with Ciprofloxacin (HY-B0356) in the bacteremia model infected with P. aeruginosa PAO1[1].