Sahu Susanta Kumar, Pandeya Surendra Nath, Pathak Ashish Kumar
A series of N-substituted piperazinyl Schiff bases of gatifloxacin were designed and were docked within the “Quinolone Resistance Determining Region” (QRDR) of E. coli DNA Gyrase-A (EcGyr-A) chain (QRDR-A), to evaluate the possible relationship between docking scores and their contribution to biological activity, along with the interaction with target residues. The obtained docking scores of analogues were compared with score of reference ligand gatifloxacin, under identical experimental sets. The analogue with 2-(pyridin-4-ylcarbonyl) hydrazinylidene substituents, 1h showed highest docking score (-167.66 kcal.mol-1). Compounds with substituents 2-hydroxyimino, 1b and 2-carbamothioylhydrazinylidene, 1d showed moderate docking score (-161.32 kcal.mol-1 and -158.64 kcal.mol-1 respectively) against QRDR-A. Among the eight analogues selected for docking studies, a moderate correlation was also observed between docking scores and experimental biological activity reported in our previous work. Further structural analysis of docking studies on our compounds suggests attractive starting point to find new lead compounds with potential improvements.
