Synthesis, characterization and biological evaluation of new heterocyclic compounds containing benzimidazole ring

• Published in: Journal of pharmaceutical sciences and research 2018-06, Vol.10 (6), p.1356-1359
• Main Authors: Redayan, Muayed Ahmed, Razak, Waseela Abdul Redah abdul, lafta, Ashraf Tark
• Format: Article
• Language: English
• Subjects: Amino acids; Biochemistry; Biological activity; Cancer; Chemistry; Ethanol; Pharmaceutical sciences; Phenols; Solvents
• ISSN: 0975-1459

Some selected compounds were tested in vitro for their antibacterial activity by disc diffusion method against two types of Gram-positive bacteria namely (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria namely (Pseudomonas aeruginosa, Escherichia coli). Schiff bases considered as privileged structure of organic compounds, especially in the medicinal and pharmaceutical field. [...]synthesis and development of novel Schiff base derivatives as potential chemotherapeutics still attract attention of organic and medicinal and wide range of biological activities including antibacterial [18] and antimicrobial [19]. The Schiff bases compounds 2(a-l) were synthesized by the condensation reaction of compounds 1(a-d) with corresponding aromatic aldehyde in the presence of ethanol and few drops of acetic acid .the structure of all compounds 2(a-l) was confirmed by its IR spectra and compounds 2(b,d,e,h,i,l) by 1H and 13CNMR, The IR spectra of these compounds exhibited broad absorption band at (3211-3365)cm-1 was attributed to the N-H imidazole group and band at(1608-1633) which assigned to imine group(N=CH).In 1H-NMR spectra of compounds 2(b,d,e,h,i,l), the presence of proton of N=CH group was confirmed by one proton singlet at (8.39 -9.51)ppm, while signal for imidazole protons of NH group can be observed at ( 5.6-5.93),. The 13C-NMR spectra of compounds 2(b,d,e,h,i,l) exhibited signals at(5 156.7-167.7 ppm) which attributed to the imine group ( -N=CH-),and showed signal at about (5138.3 - 149.7 ppm) related to benzimidazole (C=N) group,.In 13CNMR, DEPT-135 of compounds(2b,2h,2i and 2l)show negative signals at around (47.1 - 49.5) for CH2 group Antibacterial activity The disk diffusion method was used to screened antibacterial activities of the some compounds synthesized herein(ref.). against different strains of Gram-positive bacteria namely (Staphylococcous aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli) The compounds were tested at concentration of (10 mg /ml and 100 mg /ml ).