Design, Synthesis and Biological Evaluation of Potent Piperazine-Based BioA Inhibitors Targeting Biotin Biosynthesis in Mycobacterium tuberculosis.

We recently reported C48, a potent and orally effective inhibitor targeting biotin biosynthesis in Mycobacterium tuberculosis (Mtb). Notably, C48 exhibited a favorable pharmacokinetic profile and suppressed Mtb growth in a mouse model that recapitulates human biotin physiology, demonstrating that biotin is a validated target for antibacterial agents. This paper details the previously undisclosed lead optimization studies, which employed rational drug design by the strategic introduction of fluorine, reduction of rotatable bonds, and incorporation of nitrogen atom to enhance π-π stacking. A series of novel BioA inhibitors were designed, synthesized, and evaluated with respect to their biochemical properties, in vitro ADME, and pharmacokinetic profiles. Key analogues were tested against isogenic Mtb strains (BioA underexpressed or overexpressed) to confirm on-target engagement. C48 emerged as the most potent candidate with minimum inhibitory concentrations (MICs) ranging from 0.012 to 0.093 μM against a panel of drug-sensitive and drug-resistant Mtb strains.