Synthesis, Characterization and Biological Studies of Some New N-Bridged Heterocycles

Abstract

Antibiotics, first introduced in the 1940s, dramatically reduced illnesses and deaths caused by bacterial infections. Before the introduction of antibiotics, infectious diseases claimed countless victims. But a hallmark of antibiotics is that they lose their effectiveness over time as bacteria naturally evolve and mutate and so become resistant to the medicine's effects. The rate of growth of antimicrobial resistance has accelerated due to the widespread global use of antibiotics. It is important to find out newer, safer and more effective antibiotics with broad-spectrum of activity. Heterocyclic compounds by virtue of their specific activity could be employed in the treatment of infectious diseases. A systematic investigation of this class of heterocyclic lead revealed that pyrazole containing pharmacoactive agents play important role in medicinal chemistry. The prevalence of pyrazole cores in biologically active molecules has stimulated the need for elegant and efficient ways to make these heterocyclic lead. Owing to the pharmacological importance of pyrazole and its derivatives, in the present work, it has been contemplated to couple various biologically active heterocyclic moieties with pyrazole through active functional systems to form a new molecular framework. Accordingly, different series, viz. triazolothiadiazole (P1-10), oxadiazole (P11-24), thiazole (P25-38), Schiff base (P39-48), Cyanopyridone (P49-63) and pyrazoline derivatives (P64-74) carrying pyrazole ring as core structure have been designed and synthesized. Structures of the newly synthesized compounds were confirmed by FT-IR, 1H NMR, 13C NMR, mass spectral studies followed by elemental analyses. The newly synthesized compounds were tested for their antimicrobial activity. Selected compounds were also screened for anti-inflammatory and antioxidant activity. Some of the synthesized compounds were found to exhibit potent activity. The acute oral toxicity study for few of the biologically active compounds was also performed. Molecular docking studies of selected compounds were carried out for better understanding of the drug-receptor interaction.