Synthesis and investigation of antimicrobial properties of pyrrolidine appended calix[4]arene

Abstract

Background: Calixarenes are widely used macromolecules in supramolecular chemistry synthesized by simple phenol formaldehyde condensation reaction in the presence of base. This article describes the synthesis, antibacterial, and antifungal properties of calix[4]arene appended with pyrrolidine at the upper rim (CAP3). Methods: Antimicrobial activity of CAP3 was determined by Kirby-Bauer well agar diffusion method in Mueller-Hinton agar (MHA) medium of growth against Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 10231) and Streptococcus viridans (ATCC 12392), Candida albicans (ATCC 32333), Aspergillus niger (ATCC 16404), and Aspergillus flavus (ATCC 90906). Structure–activity relationship was also used to evaluate the active site of CAP3. Results: Bacterial strains have shown minimum inhibitory concentration (MIC) values in 1.17–2.34 mg/mL range; whereas, the fungal strains have shown MIC values at the range of 0.58-2.34 mg/mL. It is observed that CAP3 has excellent antifungal action for A. niger as well as antibacterial action for S. viridans having MIC values of 0.58 and 1.17 mg/mL, respectively. The SAR (structure–activity relationship) study of compound reveals that there is a significant antimicrobial activity shown by CAP3 probably due to the pyrrolidine substituents at phenyl rings of calix[4]arene. Conclusions: The results indicate that CAP3 is an effective material against the microbial strains.