Antileishmanial evaluation of clubbed bis(indolyl)-pyridine derivatives: One-pot synthesis, in vitro biological evaluations and in silico ADME prediction.

A new series of bis(indolyl)-pyridine derivatives 6(a-m) were synthesized by Chichibabin reaction process and evaluated for antileishmanial and antibacterial activities to establish structure-activity relationship. The synthesis was carried out through one-pot multicomponent reaction of 3-acetylindole, aromatic aldehydes, and ammonium acetate in the presence of camphor-10-sulfonic acid as a catalyst. The compounds 6d (IC50=102.47μM) and 6f (IC50=99.49μM) had shown promising antileishmanial against L. donovani promastigotes when compared with standard sodium stibogluconate (IC50=490.00μM). All the synthesized compounds (MIC range=41.35-228.69μg/mL) had shown potent antibacterial activity than standard ampicillin (MIC range=100.00-250.00μg/mL) against all the tested bacterial strains. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.