4. Conclusions

The virtual screening of the investigated compounds using docking has been carried out with CLC Drug Discovery Workbench Software and has led to the identification of quinolone derivatives for inhibiting the activities of topoisomerase I and topoisomerase IV. It was observed that the presence of the benzyl substituent in N1 position of the 7-(4-methyl-piperidinyl)-quinolones core leads to increased docking score against human DNA topoisomerase and topoisomerase IV from Klebsiella pneumoniae.

The compounds PQ11 (1-benzyl-6-fluoro-7-(4-methyl-piperidin-1-yl)-1,4 dihydro-4-oxo-quinolin-3-carboxylic acid), 6ClPQ11 (1-benzyl-6-chloro-7- (4-methyl-piperidin-1-yl)-1,4-dihydro-4-oxo-quinolin-3-carboxylic acid), HPQ11 (1-benzyl-7-(4-methyl-piperidin-1-yl)-1,4-dihydro-4-oxo-quinolin-3-carboxylic acid), and 6MePQ11 (1-benzyl-6-methyl-7-(4-methyl-piperidin-1-yl)-1,4-dihydro-4-oxo-quinolin-3-carboxylic acid) reveal better docking scores than that of the reference ligands, topotecan (TTC) and levofloxacin (LFX), docked on human DNA topoisomerase (PDB ID: 1K4T) and topoisomerase IV (PDB ID: 5EIX) from Klebsiella pneumoniae, respectively.
