The optimization and characterization of functionalized sulfonamides derived from sulfaphenazole against Mycobacterium tuberculosis with reduced CYP 2C9 inhibition

In this study, a series of sulfonamide compounds was designed and synthesized through the systematic optimization of the antibacterial agent sulfaphenazole for the treatment of Mycobacterium tuberculosis (M. tuberculosis). Preliminary results indicate that the 4-aminobenzenesulfonamide moiety plays a key role in maintaining antimycobacterial activity. Compounds 10c, 10d, 10f and 10i through the optimization on phenyl ring at the R² site on the pyrazole displayed promising antimycobacterial activity paired with low cytotoxicity. In particular, compound 10d displayed good activity (MIC = 5.69 μg/mL) with low inhibition of CYP 2C9 (IC₅₀ > 10 μM), consequently low potential risk of drug-drug interaction. These promising results provide new insight into the combination regimen using sulfonamide as one component for the treatment of M. tuberculosis.