Enhanced fluorescence norfloxacin substituted naphthalimide derivatives: Molecular docking and antibacterial activity

Hybrid derivatives are a fascinating and challenging process in the area of drug discovery. Naphthalimide derivatives with modified norfloxacin moiety were designed and synthesized. Docking simulations were done to assess the interactions of the derivatives with the E. coil type II topoisomerases Gyrase B and ParE ATP-binding pocket by taking novobiocin as a standard molecule. Results suggested that the norfloxacin substituted naphthalimide derivatives indicate red-shift emission maxima when compared to 4-bromo 1,8-naphthalic anhydride. The molecular docking simulation study revealed that the derivatives have similar interaction but a different mode of binding with the gyrase B ATP-binding pocket as compare to novobiocin. However, they bound to ParE ATP-binding pocket similarly to novobiocin. The antibacterial property was confirmed with disc diffusion method. Our study indicated that the norfloxacin substituted naphthalimide novel derivatives have pronounced fluorescence, anti-topoisomerase activity, and antibacterial properties; therefore, they could be developed into new drug candidates. (C) 2017 Elsevier B.V. All rights reserved.