Evaluation of Antibacterial and Antifungal Activity of New derivatives of two, three and four components of ۱, ۳, ۴-oxadiazoles

The emergence of antibiotic resistance in the treatment of diseases has become a serious problem; therefore, in the current situation, the discovery and presentation of alternative structures is very important. The aim of this study was to investigate the new ۱, ۳, ۴-oxadiazole structures against bacteria and fungi resistant to treatment. Twelve new derivatives were obtained by single-step synthesis and their structure was evaluated by IR (Infrared), C-NMR (Carbon Nuclear Magnetic Resonance) and H-NMR (Hydrogen Proton Nuclear Magnetic Resonance).Then, to measure the antibacterial and antifungal activity of prepared derivatives agar well diffusion method was employed, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined at a concentration of ۰.۱mg/mL with three replications on Streptococcus Mutans, Enterococcus Faecalis, Klebsiella Pneumoniae, Escherichia Coli O۱۵۷: H۷, Candida Glabrata, Candida Krusei. Statistical analysis of the data was performed using (IBM SPSS Statistics ۲۲). The results showed that the best antibacterial activity among all compounds was related to the ۴g compound against the E.faecalis (IZ= ۴۵.۳۳ ± ۱.۱۵ mm), (MIC: ۲۵۰μg /ml), that showed inhibition zones greater than the control.The compound (۴g) also showed acceptable activity on the S. mutans (IZ= ۲۵.۶۶ ± ۰.۵۷ mm) (MIC: ۱۲۵ μg/ml), and other bacteria were affected too .In the case of fungal specimens, no acceptable results were obtained. Based on the results of this study, the compound ۴g (with the chlorophenyl and morpholine functional groups) can be used as an alternative to the ability to inhibit gram-positive bacteria resistant to antibiotics.

Keywords:

Antibiotic Resistance , Enterococcus faecalis , Streptococcus mutans , chlorophenyl , morpholine