Synthesis and biological evaluation of novel fused indolo [3, 2-c] [1,8] naphthyridine derivatives as potential antibacterial agents

<p>Nine novel fused indolo [1,8] naphthyridine derivatives were synthesized using the Povarov reaction, in a one-pot system, and were fully characterized by spectroscopic techniques such as FT-IR, NMR, TOF-MS, and elemental analysis. Furthermore, their antibacterial activities against six bacterial strains were assessed. The results of the bioassay demonstrated that compounds <b>4a</b>, <b>4c</b>, and <b>4i</b> showed good inhibitory effect with a MIC value ranging from 0.04687 to 0.09375 µM against <i>Bacillus cereus</i> and <i>Staphylococcus aureus</i>. The toxicity of <b>4a–i</b>, evaluated through mutagenicity test against <i>Salmonella typhimurium</i> TA 98 and TA100 strains, revealed that there was no significant increase in the number of revertant colonies in comparison with the control, sodium azide.</p>