Benzimidazole-based antibacterial agents against Francisella tularensis
摘要:
Francisella tularensis is a highly virulent pathogenic bacterium. In order to identify novel potential antibacterial agents against F. tularensis, libraries of trisubstituted benzimidazoles were screened against F. tularensis LVS strain. In a preliminary screening assay, remarkably, 23 of 2,5,6- and 2,5,7-trisubstituted benzimidazoles showed excellent activity exhibiting greater than 90% growth inhibition at 1 mu g/mL. Among those hits, 21 compounds showed MIC90 values in the range of 0.35-48.6 mu g/mL after accurate MIC determination. In ex vivo efficacy assays, four of these compounds exhibited 2-3 log reduction in colony forming units (CFU) per mL at concentrations of 10 and 50 mu g/mL. (C) 2013 Elsevier Ltd. All rights reserved.
SAR Studies on Trisubstituted Benzimidazoles as Inhibitors of <i>Mtb</i> FtsZ for the Development of Novel Antitubercular Agents
作者:Divya Awasthi、Kunal Kumar、Susan E. Knudson、Richard A. Slayden、Iwao Ojima
DOI:10.1021/jm401468w
日期:2013.12.12
FtsZ, an essential protein for bacterial cell division, is a highly promising therapeutic target, especially for the discovery and development of new-generation anti-TB agents. Following up the identification of two lead 2,5,6-trisubstituted benzimidazoles, 1 and 2, targeting Mtb-FtsZ in our previous study, an extensive SAR study for optimization of these lead compounds was performed through systematic modification of the 5 and 6 positions. This study has successfully led to the discovery of a highly potent advanced lead 5f (MIC = 0.06 mu g/mL) and several other compounds with comparable potencies. These advanced lead compounds possess a dimethylamino group at the 6 position. The functional groups at the 5 position exhibit substantial effects on the antibacterial activity as well. In vitro experiments such as the FtsZ polymerization inhibitory assay and TEM analysis of Mtb-FtsZ treated with 5f and others indicate that Mtb-FtsZ is the molecular target for their antibacterial activity.