Antimycobacterial activity of nitrogen heterocycles derivatives: Bipyridine derivatives. Part III [13,14]

Three classes of fused bipyridine heterocycles were designed, synthesized and evaluated for their anti-mycobacterial activities. The method for preparation of fused bipyridine derivatives is straight and efficient. The primary antimycobacterial screening reveals that mono-indolizine mono-salts are displaying potency superior to the second-line antitubercular drugs Cycloserine and Pyrimethamine and, equal as the first line anti-TB Ethambutol. The data from Cycle-2 screening assay (MIC, MBC, LORA, intracellular (macrophage) drug screening, and MTT cell proliferation) confirm the promising anti-TB results from Cycle-1 for mono-indolizine mono-salts. These data indicate that mono-indolizine monosalt 6d is a potent compound against both replicating and non-replicating Mycobacterium tuberculosis, is active against both extracellular and intracellular organisms, has a bacteriostatic mechanism of action and has basically no toxicity. We see no influence concerning the anti-TB activity of the fused-pyridine substituents. (C) 2013 Elsevier Masson SAS. All rights reserved.