Exploring Novel Pyrazole-Fused 1H-tetrazol-5-yl: Synthesis, SAR and Antimicrobial Efficacy

Abstract

In this study, we present the synthesis, and biological activity of pyrazole-linked tetrazole derivatives (6A-6Q). All derivatives were screened for their antimicrobial activity against both gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella spp.). The compounds were synthesized through a five-step reaction process and further characterized using 1H NMR and LCMS spectral techniques. The synthetic compounds 6A–6Q were evaluated for their experimental antimicrobial activity, with ampicillin used as a positive control. According to the in vitro assays, compounds 6D and 6E exhibited higher activity against all tested strains due to the presence of halogens at the meta position. Molecules 6A, 6C, 6J, 6K, and 6E demonstrated good to moderate antibacterial activity based on their structure-activity relationship (SAR) studies. Conversely, compounds 6G, 6H, 6I, and 6P showed lower inhibition due to the presence of electron-donating groups in their structures towards the tested bacteria.