Discovery of a cofactor-independent inhibitor ofMycobacterium tuberculosisInhA.
Xia, Y., Zhou, Y., Carter, D.S., McNeil, M.B., Choi, W., Halladay, J., Berry, P.W., Mao, W., Hernandez, V., O'Malley, T., Korkegian, A., Sunde, B., Flint, L., Woolhiser, L.K., Scherman, M.S., Gruppo, V., Hastings, C., Robertson, G.T., Ioerger, T.R., Sacchettini, J., Tonge, P.J., Lenaerts, A.J., Parish, T., Alley, M.(2018) Life Sci Alliance 1: e201800025-e201800025
- PubMed: 30456352 
- DOI: https://doi.org/10.26508/lsa.201800025
- Primary Citation of Related Structures:  
5VRL, 5VRM, 5VRN - PubMed Abstract: 
New antitubercular agents are needed to combat the spread of multidrug- and extensively drug-resistant strains of Mycobacterium tuberculosis . The frontline antitubercular drug isoniazid (INH) targets the mycobacterial enoyl-ACP reductase, InhA. Resistance to INH is predominantly through mutations affecting the prodrug-activating enzyme KatG. Here, we report the identification of the diazaborines as a new class of direct InhA inhibitors. The lead compound, AN12855, exhibited in vitro bactericidal activity against replicating bacteria and was active against several drug-resistant clinical isolates. Biophysical and structural investigations revealed that AN12855 binds to and inhibits the substrate-binding site of InhA in a cofactor-independent manner. AN12855 showed good drug exposure after i.v. and oral delivery, with 53% oral bioavailability. Delivered orally, AN12855 exhibited dose-dependent efficacy in both an acute and chronic murine model of tuberculosis infection that was comparable with INH. Combined, AN12855 is a promising candidate for the development of new antitubercular agents.
Organizational Affiliation: 
Anacor Pharmaceuticals, Palo Alto, CA, USA.