Highly Potent and Selective <i>N</i>-Aryl Oxamic Acid-Based Inhibitors for <i>Mycobacterium tuberculosis</i> Protein Tyrosine Phosphatase B

Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis (Mtb). Mtb protein tyrosine phosphatase B (mPTPB) is a virulence factor required for Mtb survival in host macrophages. Consequently, mPTPB represents an exciting target for tuberculosis treatment. Here, we identified N -phenyl oxamic acid as a highly potent and selective monoacid-based phosphotyrosine mimetic for mPTPB inhibition. SAR studies on the initial hit, compound 4 (IC 50 = 257 nM), resulted in several highly potent inhibitors with IC 50 values lower than 20 nM for mPTPB. Among them, compound 4t showed a K i of 2.7 nM for mPTPB with over 4500-fold preference over 25 mammalian PTPs. Kinetic, molecular docking, and site-directed mutagenesis analyses confirmed these compounds as active site-directed reversible inhibitors of mPTPB. These inhibitors can reverse the altered host cell immune responses induced by the bacterial phosphatase. Furthermore, the inhibitors possess molecular weights D 7.4 0.43, and good aqueous solubility and metabolic stability, thus offering excellent starting points for further therapeutic development.