Design, Synthesis and Molecular Docking Studies of Some Thiazole Clubbed Heterocyclic Compounds as Possible Anti-infective Agents

The present work describes synthesis of a series of 5-((1-(4-(4-chlorophenyl)thiazol-2-yl)-3- aryl-1H-pyrazol-4-yl)methylene)-2-(arylimino)thiazolidin-4-one derivatives and their molecular docking and biological evaluation as possible antimalarial, anthelmintic and antimicrobial agents. The synthesis of compounds has been accomplished by adopting suitable synthetic methods. Structures of newly synthesized compounds were characterized and authenticated by spectral methods such as IR, 1H-NMR and mass spectra. Synthesized compounds were screened for their in vitro antimicrobial activity against selected bacterial strains and fungal strains viz. B. subtilis, S. aureus, E. coli, P. fluorescens, C. albicans, C. glabrata and antimalarial studies against P. falciparum. Titled compounds were also tested against Pheretima posthuma (earthworm) for their anthelmintic activity. Molecular docking was done to study the binding modes of the potent compounds against Escherichia coli (PDB ID: 1AB4) and Candida P450DM (PDB ID: 1EA1) enzymes. The results revealed that all the compounds exhibited moderate to significant antimicrobial activities. Antimalarial activity screening revealed that one compound 8i showed significant antimalarial activity with of IC50; 0.59 μg/mL as compared to standard drugs chloroquine (IC50= 0.020 μg/mL) and quinine (IC50; 0.268 μg/mL). The most active compound exhibited the mean paralysis time of 19.2 ± 0.9 min and mean death time of 31.7 ± 2.5 min. It can be concluded that some of the synthesized compounds have remarkable antiinfective, antimalarial and anthelmintic activity and are suitable candidates for further scientific exploration.