MSU-43557 is a Mycobacterium abscessus MmpL3 ( MAB_4508 ) inhibitor and bactericidal agent. MSU-43557 inhibits MmpL3 function, disrupts trehalose monomycolate synthesis, and reduces biofilm-associated Mycobacterium abscessus viability. MSU-43557 exerts bactericidal activity against intracellular Mycobacterium abscessus. MSU-43557 shows low eukaryotic cytotoxicity and low Mycobacterium abscessus resistance frequency. MSU-43557 can be used for the research of mycobacterium abscessus infection [1].
In Vitro, MSU-43557 (80 μM-0.08 nM; 3 d) potently inhibits the growth of Mycobacterium abscessus ATCC 19977 in vitro, and exhibits time-dependent bactericidal activity at a concentration of 5× MIC; meanwhile, MSU-43557 potently inhibits strains of Mycobacterium tuberculosis, Mycobacterium abscessus and Mycobacterium smegmatis, shows no activity against non-mycobacterial species within 80 μM, and displays variable inhibitory activity against clinically isolated multidrug-resistant Mycobacterium abscessus strains[1]. MSU-43557 (0.18 nM-160 μM; 3 d) disrupts mature Mycobacterium abscessus biofilms with an EC50 of 8.66 μM; it also reduces bacterial viability within biofilms, with a corresponding EC50 of 0.16 μM[1]. MSU-43557 (0.18 nM-160 μM; 3 d) kills intracellular Mycobacterium abscessus ATCC 19977 in mouse bone marrow-derived macrophages with an EC50 of 0.39 μM, and exhibits low cytotoxicity toward mouse bone marrow-derived macrophages[1].
References:
[1]. Abdalla BJ, et al. Defining the Mechanism of Action and Resistance of New Mycobacterium abscessus MmpL3 Inhibitors. ACS Chem Biol. 2026 Feb 20;21(2):284-301.
In Vitro, MSU-43557 (80 μM-0.08 nM; 3 d) potently inhibits the growth of Mycobacterium abscessus ATCC 19977 in vitro, and exhibits time-dependent bactericidal activity at a concentration of 5× MIC; meanwhile, MSU-43557 potently inhibits strains of Mycobacterium tuberculosis, Mycobacterium abscessus and Mycobacterium smegmatis, shows no activity against non-mycobacterial species within 80 μM, and displays variable inhibitory activity against clinically isolated multidrug-resistant Mycobacterium abscessus strains[1]. MSU-43557 (0.18 nM-160 μM; 3 d) disrupts mature Mycobacterium abscessus biofilms with an EC50 of 8.66 μM; it also reduces bacterial viability within biofilms, with a corresponding EC50 of 0.16 μM[1]. MSU-43557 (0.18 nM-160 μM; 3 d) kills intracellular Mycobacterium abscessus ATCC 19977 in mouse bone marrow-derived macrophages with an EC50 of 0.39 μM, and exhibits low cytotoxicity toward mouse bone marrow-derived macrophages[1].
References:
[1]. Abdalla BJ, et al. Defining the Mechanism of Action and Resistance of New Mycobacterium abscessus MmpL3 Inhibitors. ACS Chem Biol. 2026 Feb 20;21(2):284-301.