MsbA-IN-6 is a potent antibiotic and inhibitor of the gram-negative ATP-binding cassette (ABC) transporter MsbA, an essential protein required for transporting lipopolysaccharide across the inner bacterial membrane. It exerts its bactericidal effect on Escherichia coli by inhibiting the ATPase and transport activity of MsbA, while retaining efficacy against multidrug-resistant clinical strains [1] [2].