The control of antimicrobial resistance (AMR) seems to have come to a dead end. The major consequences of the use and abuse of antibacterial drugs are the development of resistant strains due to genetic mutability of both pathogenic and nonpathogenic microorganisms. We, herein, report the synthesis, characterization and biological activities of coumarin-thiazole-pyrazole (CTP) molecular hybrids with an effort to explore and overcome the increasing antimicrobial resistance. The compounds were characterized by analyzing their IR, Mass, ¹H and¹³C NMR spectral data and elemental analysis. The in vitro antimicrobial activity of the synthesized compounds was investigated against various pathogenic strains; the results obtained were further explained with the help of DFT and molecular orbital calculations. Compound 1b and 1f displayed good antimicrobial activity and synergistic effects when used with kanamycin and amphotericin B. Furthermore, in vitro cytotoxicity of compounds 1b and 1f were studied against HeLa cells (cervical cancer cell) and Hek-293 cells. The results of molecular docking study were used to better rationalize the action and prediction of the binding modes of these compounds.

Marine natural products have proven to be a rich source of drugs and drug leads. These natural products are secondary metabolites and show biological activity against bacteria, fungi and viruses. Natural products containing thiazole ring occur often in marine sources. They exhibit diverse and remarkable biological activities, including antitumor, antibacterial, anti-inflammatory and cytotoxic activities, to name a few. This review surveys the natural thiazole derivatives that have been isolated from marine microorganisms, with emphasis on biological implications in last three decades.