The natural and synthetic indole weaponry against bacteria

The emergence of drug resistant bacterial infections leading to high mortality rates has posed a formidable challenge to organic synthesis and medicinal chemists to deliver potent and novel antibacterial drug candidates. In particular, antibacterial agents based on novel chemotypes and first-in-class drug candidates with novel mode of actions are highly desired. Indole scaffold has found a consistent presence in the bioactive molecules of synthetic and natural origin. The potential of indole based small molecules as antibacterial agents has not been as much explored as in other areas of medicine, like cancer therapy. In this review, we present a brief account of indole based antibacterial small molecules which have been either synthesized in the laboratory or isolated from natural sources and provide intriguing potential leads in the antibiotic drug discovery research.