Design, synthesis and biological evaluation of 8-aminoquinoline-1,2,3-triazole hybrid derivatives as potential antimicrobial agents

Abstract

A library of 20 novel quinoline-1,2,3-triazole hybrid compounds were synthesized by starting from 8-aminoquinoline to discover new pharmacophores exhibiting antimicrobial activities. Effective and targeted selective biologically active molecules through conjugation of diversely substituted triazoles and 8-aminoquinoline were achieved successfully with 1,4-disubstituted regioisomer product in the 3 + 2 cycloaddition reaction, as expected. All the synthesized compounds were evaluated for antimicrobial activity against different antibacterial and antifungal pathogenic strains. Pleasingly, the compound 9a was found as the most potent against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis, Staphylococcus aureus, Streptococcus pneumoniae, Bacillus subtilis, Candida albicans and Candida parapsilosis strains. Preliminary screening results indicated that triazole linked quinoline compounds demonstrate promising antimicrobial activities against Gram (+) and Gram (-) bacterial and fungi strains. Furthermore, the pharmacokinetic properties of the quinoline-1,2,3-triazole hybrid compounds were analyzed to evaluate their potential as drug candidates, which indicated that all compounds are in agreement with Lipinski's rule of five.