Synthesis, antimicrobial evaluation, and in silico studies of quinoline-1H-1,2,3-triazole molecular hybrids

Antimicrobial resistance has become a significant threat to global public health, thus precipitating an exigent need for new drugs with improved therapeutic efficacy. In this regard, molecular hybridization is deemed as a viable strategy to afford multi-target-based drug candidates. Herein, we report a library of quinoline-1H-1,2,3-triazole molecular hybrids synthesized via copper(I)-catalyzed azide-alkyne [3 + 2] dipolar cycloaddition reaction (CuAAC). Antimicrobial evaluation identified compound 16 as the most active hybrid in the library with a broad-spectrum antibacterial activity at an MIC₈₀ value of 75.39 μM against methicillin-resistant S. aureus, E. coli, A. baumannii, and multidrug-resistant K. pneumoniae. The compound also showed interesting antifungal profile against C. albicans and C. neoformans at an MIC₈₀ value of 37.69 and 2.36 μM, respectively, superior to fluconazole. In vitro toxicity profiling revealed non-hemolytic activity against human red blood cells (hRBC) but partial cytotoxicity to human embryonic kidney cells (HEK293). Additionally, in silico studies predicted excellent drug-like properties and the importance of triazole ring in stabilizing the complexation with target proteins. Overall, these results present compound 16 as a promising scaffold on which other molecules can be modeled to deliver new antimicrobial agents with improved potency.