JOURNAL OF PHARMACOLOGY AND
BIOMEDICINE
ISSN.2456-8244
The emergence of multidrug-resistant (MDR) pathogens has created an urgent need for novel antimicrobial agents with improved efficacy. In this study, a series of thiadiazole-conjugated imidazole derivatives (5a–5e) were synthesized and evaluated for antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The synthetic route involved sequential preparation of substituted imidazoles, followed by conjugation with thiadiazole moieties. Structural confirmation was achieved through FTIR, ^1H NMR, and mass spectrometry analyses. Antibacterial activity was assessed using disc diffusion and broth dilution methods. Among the synthesized compounds, derivative 5e (bearing a methoxy substituent) exhibited the most promising activity, with inhibition zones up to 26 mm and IC₅₀ values of 67.83 µg/mL (E. coli) and 63.56 µg/mL (S. aureus). Structure–activity relationship (SAR) analysis revealed that electron-donating substituents enhanced antibacterial potency, whereas electron- withdrawing groups diminished activity. Although less potent than ciprofloxacin, compound 5e represents a promising scaffold for further optimization toward next-generation antimicrobial agents.
NAMES:
ONLINE ISSN:24568244
Keywords: Thiadiazole, antimicrobial, imidazole, structure activity relationship, zone of inhibition
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