Anticancer, antimicrobial activities of quinoline based hydrazone analogues: Synthesis, characterization and...

Based on the biologically active heterocycle quinoline, a series (18a-p) of quinoline hydrazone analogues were prepared, starting from 6-bromo/6-chloro-2-methyl-quinolin-4-yl-hydrazines. For all the newly synthesized compounds cytotoxic activities were carried out at the National Cancer Institute (NCI), USA, against full NCI 60 human cancer cell lines. Amongst all the tested compounds, nine compounds (18b, 18d, 18e, 18f, 18g, 18h, 18i, 18j, 18l) exhibited important anti-proliferative activity at 10 µM concentration and were further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 µM) with GI₅₀ values ranging from 0.33 to 4.87 µM and LC₅₀ values ranging from 4.67 µM to >100j µM. Further, the mean values of GI₅₀, TGI and LC₅₀ of the most potent compound 18j were compared with the clinically used anticancer agents bendamustine and chlorambucil, revealed that the quinolyl hydrazones holds promise as a potential anticancer agents. Further all the newly prepared compounds were screened for their antimicrobial activity. All the quinolyl hydrazones displayed good to excellent antimicrobial activity with MIC values ranging from 6.25 to 100 µg/mL against the tested pathogenic strains. Molecular docking of the synthesized compounds into the active binding site of human DNA topoisomerase I (htopoI) was carried out to predict the binding mode to the DNA topoisomerase I inhibitors. Hopefully in future, compounds based on quinoline core could be used as a lead compounds for designing new anticancer agents.