Recent Progress on the Development of Novel Antitubercular Agents from Whole-Cell Screening Hits

Abstract

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) continues to be a serious major global health risk. More than one-third of the world’s human population is infected, resulting in 1.4-2.0 million deaths per year. The first-line therapy using a multidrug regimen has existed since the 1970s, however, there has been an alarming increase in the number of patients with multi (MDR)- and extensive (XDR)-drug-resistant TB in recent years. Hence, there is an urgent need to develop novel drugs with new mechanisms of action and new chemotypes in order to combat drug-resistant TB. A target-based approach to finding new anti-TB agents has been widely used, however this approach has not led to the identification of clinical candidates. The recent trend has been to go back to whole-cell screens, in which compounds are identified based on their anti-TB activity. Consequently, various groups have reported structurally diverse active compounds against Mtb, which were originally identified from phenotypic screens. This review will cover recent scientific accounts published from these groups that have described medicinal chemistry optimization studies from whole-cell screening hits. In vivo pharmacokinetics and efficacy of optimized compounds as well as their potential molecular targets will be also discussed.