Novel Methodology for Synthesis and Computational Analysis of Zinc Complexes of Isatin Derivatives and Screening their Biological Activity

Background: Due to arising threats of microbial infectious diseases in the human population and the development of resistance against therapeutics, novel medicinal agents are required to counteract antimicrobial resistance. Heterocyclic rings, such as indole or pyrrole, have been acknowledged to possess various biological properties, like antimicrobial, anticancer, antiviral, antitubercular, etc., and metals, such as platinum, vanadium, zinc, selenium, etc., also show therapeutic actions. Thus, this work focuses on turning a heterocyclic ring compound (isatin) and metal (zinc) into a drug having antimicrobial potential. Objective: The objective of the study was to synthesize zinc complexes of isatin Schiff bases and evaluate their antibacterial and antifungal activity. Methods: Herein, the conventional method was used for the synthesis of isatin Schiff bases from isatin and different monosubstituted amines. Then, zinc complexes were prepared by using isatin Schiff bases and zinc acetate. Physicochemical characteristics, such as Rf value and melting point, were determined by TLC and decibel melting point apparatus, respectively. All the complexes were characterized by FT-IR and 1H NMR techniques. Further, the final zinc complexes were screened for antimicrobial potential by the serial dilution method. Some computational studies were also done with the help of MOPAC 2016. Results: In the present work, 14 complexes of zinc were obtained in harmonious yield from isatin Schiff bases using zinc acetate. Amongst the studied complexes, Z-3, Z-4, and Z-12 depicted maximum antimicrobial activity. Conclusion: 14 complexes of zinc were prepared by using 14 isatin Schiff bases, which were, in turn, prepared by isatin and different mono-substituted amines. Characterization of these complexes was done by using FT-IR and 1H NMR. All prepared metal complexes were obtained in appropriate yield. The synthesized complexes were screened for their antimicrobial potential.