Indolyl-4H-Chromene Derivatives as Antibacterial Agents: Synthesis, in Vitro and in Silico Studies.

In this study, indolyl-4H-chromene derivatives are designed and synthesised using an eco-friendly multicomponent one-pot synthesis using benzaldehydes, nitroketene N, S-acetals, and indoles combine with InCl3 , a Lewis acid catalyst, and ethanol, an environmentally acceptable solvent. Due to antibiotic resistance, assessed these Indolyl-4H-chromene derivatives for their in vitro antibacterial activity against Gram-positive and Gram-negative bacteria, including Streptococcus pyogenes, Staphylococcus aureus, Clostridium pyrogenes, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, using the agar well diffusion method and Minimum Inhibition Concentration (MIC) assay. Three compounds, 4-(1H-indol-3-yl)-6-methoxy-N-methyl-3-nitro-4H-chromen-2-amine, 4-(1H-indol-3-yl)-3-nitro-N-phenyl-4H-chromen-2-amine and 4-(6-Fluoro-1H-Indol-3-yl)-N-methyl-3-nitro-4H-chromen-2-amine showed better zone of inhibition (mm) and Minimum Inhibition Concentration (MIC) values of 10 µg/mL to 25 µg/mL against all bacterial types. The Ki values of 278.60 nM and 2.21 nM for compound 4-(1H-indol-3-yl)-3-nitro-N-phenyl-4H-chromen-2-amine showed improved interactions with DNA gyrase B and topoIV ParE's ATP binding sites in in silico studies.