Synthesis, Biological Screening and Docking Study of Some Novel Pyra-zolopyrano2,3-Bquinolin Derivatives as Potent Antibacterial Agents

Abstract

Background: Pyranopyrazoles have a variety of biological activities and can be obtained by various starting materials and synthetic methods. Also, pyrazolopyrano2,3-bquinolins that contain pyranopyrazole moiety have some biological activities such as anti-acetylcho-linesterase and anti-butyrylcholinesterase activity. In this research, our objective is to prepare pyranopyrazole compounds and pyrazolopyrano2,3-bquinolins in a simple way and then evaluate their antibacterial effect. Methods: In this study, pyrano2,3-cpyrazole derivatives have been synthesized by condensing malononitrile, aromatic aldehydes, and 3-methyl-1-phenyl-2-pyrazolin-5-one in the presence of magnesium perchlorate as a catalyst. Then we prepared pyrazolopyrano2,3-bquinolins via subse-quent Friedlander reaction between cyclohexanone and the obtained pyrano2,3-cpyrazoles. Also, the antimicrobial activity of the synthesized pyrazolopyrano2,3-bquinolins against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was measured. Then we studied molecular docking of them to find the predicted compounds' interactions and binding energy with DNA-gyrase with the AutoDock 4.2 software. Results: Pyrazolopyrano2,3-bquinolins were synthesized in the optimized conditions. Evaluation of their antibacterial activities showed that these compounds have moderate to good antibacterial activities against four bacteria species. Also molecular docking tests of docked compounds showed a strong bonding interaction with DNA-Gyrase and had been docked into the intercalation place of DNA of DNA-gyrase complex. The molecule bonded to the DNA stabilized by the H bonds, hydro-phobic interactions, and π-π interaction. Conclusion: We have developed an efficient and one-pot ecofriendly protocol for the synthesis of some novel pyrano2,3-cpyrazol derivatives and pyrazolopyrano2,3-bquinolins under simple conditions and then tested them for their antibacterial activities. Also, we studied molecular docking of them. These compounds showed moderate to good inhibitory action. © 2022 Bentham Science Publishers.