National Center for
4J1N: Crystal Structures Of Fabi From F. Tularensis In Complex With Novel Inhibitors Based On The Benzimidazole Scaffold
Structural and biological evaluation of a novel series of benzimidazole inhibitors of Francisella tularensis enoyl-ACP reductase (FabI)
Bioorg. Med. Chem. Lett. (2015) 25 p.1292-1296
Francisella tularensis, the causative agent of tularemia, presents a significant biological threat and is a Category A priority pathogen due to its potential for weaponization. The bacterial FASII pathway is a viable target for the development of novel antibacterial agents treating Gram-negative infections. Here we report the advancement of a promising series of benzimidazole FabI (enoyl-ACP reductase) inhibitors to a second-generation using a systematic, structure-guided lead optimization strategy, and the determination of several co-crystal structures that confirm the binding mode of designed inhibitors. These compounds display an improved low nanomolar enzymatic activity as well as promising low microgram/mL antibacterial activity against both F. tularensis and Staphylococcus aureus and its methicillin-resistant strain (MRSA). The improvements in activity accompanying structural modifications lead to a better understanding of the relationship between the chemical structure and biological activity that encompasses both enzymatic and whole-cell activity.