Biological and In silico Evaluation of Quinolinedione and Naphthoquinone Derivatives as Potent Antibacterial Agents

Quinolinequinones (Qq) and naphthoquinones (Nq) are known for their broad spectrum of biological activities and computational techniques are now used in drug research because of they are cost and time effective. In the present study, a series of anilino and aryl derivatives of quinolinequinone showed potency against a Gram negative and positive bacteria (Escherichia coli and Staphylococcus aureaus respectively) at MIC range of 1.6-25 mg/ml. Four out of twenty-four compounds inhibited both studied bacteria at MIC (1.6-12.5 mg/ml) lower than used standard drug - ampicillin (20-23 mg/ml). Docking studies showed that the four compounds demonstrated affinity for penicillin binding protein (-4.24 to -4.49 Kcal/mol) over ampicillin (-2.32 Kcal/mol). The similarity between docking and in vitro testing suggests inhibition of the protein as the mechanism of the compounds' bactericidal action. The binding poses of the compounds within the binding site of the protein revealed unique interactions with the active site residues.