LeuRS-IN-1 is a potent, orally active M. tuberculosis leucyl-tRNA synthetase (M.tb LeuRS ) inhibitor. LeuRS-IN-1 has IC 50 and Kd values of 0.06 μM, 0.075 μM for M.tb LeuRS, respectively. LeuRS-IN-1 inhibits human cytoplasmic LeuRS ( IC 50 =38.8 μM), and HepG2 protein synthesis ( EC 50 =19.6 μM).