Fourth, there were relatively few eligible studies of the dose-response analysis. These studies 3-Nitropropionic acid contained a few cohort and case-control studies. More and more in-depth studies are necessary. Tuberculosis kills nearly 2 million people annually. The World Health Organization declared TB as a global health emergency, which highlights the importance of TB as a major threat to humans. Drug resistance and patient noncompliance are two key factors that affect the success rate of conventional treatments against TB. Therefore, there is an urgent need to identify novel therapeutic targets for TB treatment as well as new drugs that could act on them. In the last decade, exoenzymes protein tyrosine phosphatase A and B have emerged as promising therapeutic targets to discover new anti-TB agents. These enzymes are secreted into the host cell by Mycobacterium tuberculosis and attenuate host immune defenses by interfering with the host signaling pathways. Thereby, PtpA and PtpB inhibition by small molecules could impact Mtb survival in the host and open the way for the development of innovative therapeutic strategies. Particularly, the localization outside of the mycobacterial cell wall, which is difficult to penetrate, AG 99 renders these enzymes attractive drug targets. In previous works we have investigated the inhibitory activity of natural compounds analogues toward PtpA and PtpB from Mtb. In particular, we have first identified potent PtpA inhibitors by screening a series of naphthylchalcones against this enzyme. Subsequently, we showed that these chalcones inhibit PtpA by means of a competitive and selective mechanism of action as well as are endowed with a significant inhibitory activity towards Mtb growth in infected macrophages. We have also demonstrated the inhibitory properties of synthetic sulfonyl-hydrazones against PtpB, identified as competitive inhibitors with Ki values between 2.5 and 15 ��M. In our last work, a hundred synthetic chalcones have been investigated for their activities against PtpA and PtpB, and six presented competitive mechanism of action with Ki values between 8 and 29 ��M. In light of recent advances in understanding the pathological involvement of these phosphatases in Mtb growth and proliferation, and following our research interest in modulating these enzymes, here we focused on the discovery and characterization of natural compounds as PtpB inhibitors.