Synthesis and Investigation of Anti-Bacterial Effects of 2-amino-5-Nitrothiophene Derivatives

Introduction: The increasing drug resistance of bacteria against different antibiotics is a cause of development of antimicrobial compounds. The aim of this study was to investigate the synthesis and evaluation of antibacterial effects of 2-amino-5-nitrothiophene derivatives against Staphylococcus aureus and Escherichia coli. Strains.   Materials & Methods: As the first stage, 2-amino-5-nitro-thiophene derivatives were synthesized. The structures of the synthesized compounds were confirmed by means of IR, 1H NMR and 13C NMR measurements. In the second phase, these compounds were evaluated for antimicrobial effects by Agar Well Diffusion Method against Staphylococcus aureus and Escherichia coli. Strains. Then, the minimum inhibitory concentration (MIC) of these compounds were evaluated.   Findings: According to our finds, reaction of malononitrile, aryl isothiocyanate and bromonitromethane in the presence of sodium ethoxide in ethanol led to preparation of compounds 4a-e. The antibacterial effects showed that all the compounds had inhibitory effects against Staphylococcus aureus.   Discussion & Conclusion: Our investigation concluded that the structure-activity relationship (SAR) results indicated that the compound 4a showed a potent antibacterial activity against Staphylococcus aureus, while this combination proved no effects on Escherichia coli. 4c and 4d compounds demonstrated an inhibitory effect on Escherichia coli strain, while the compounds 4b and 4e indicated similar effects on both the bacteria (Staphylococcus aureus and Escherichia coli). Meanwhile, efficacy of the compounds4b and 4e against Staphylococcus aureus and Escherichia coli was the same. &nbsp