Twenty-six quinoxalin derivatives were synthesized to assess their biological activities against human non-small-cell lung cancer cells (A549 cells). Compound 4b (IC50 = 11.98 ± 2.59 μM) and compound 4m (IC50 = 9.32 ± 1.56 μM) possess anticancer activity comparable to 5-fluorouracil (clinical anticancer drug) (IC50 = 4.89 ± 0.20 μM). Western blot tests further confirmed that compound 4m effectively induced apoptosis of A549 cells through mitochondrial- and caspase-3-dependent pathways. The introduction of bromo groups instead of nitro groups into the quinoxaline skeleton has been shown to provide better inhibition against lung cancer cells in this article. This modification in the molecular structure could enhance the biological activity and effectiveness of quinoxaline derivatives in the design and synthesis of anticancer drugs, making bromo-substituted quinoxalines a promising avenue for further research and development in anticancer therapeutics.
