Design, synthesis and bioactivity studies of novel triazolopyrimidinone compounds

This study was aimed to develop novel compounds to combat antimicrobial resistance, which is one of the biggest threats to global health. For this purpose, compounds bearing triazolopyrimidinone ring and N-(methylnaphthalene)piperazine (NMP) hybrids were designed and synthesized. Ten new compounds were synthesized and after proving their chemical structures were tested for antimicrobial activity using disk diffusion and microdilution method against Gram-negative bacterial strains (Escherichia coli and Pseudomonas aeruginosa), Gram-positive bacterial strains (Staphylococcus aureus and Enterococcus faecalis) and fungal strains (Candid(' albicans and Candida parapsilosis). Antibiofilm activity and ethidium bromide accumulation assay results were also determined for the selected compounds. Among the tested compounds, hybrid compound H5 showed promising activity against E. faecalis with 16-fold potency compared to its precursor, TP5. Additionally, it has statistically significant inhibition of biofilm production at 10 mu g/ml dose against E. coli and P. aeruginosa and a decreasing effect on the relative accumulation of ethidium bromide in P. aeruginosa at 100 mu g/ml dose (85.07%) after 30 min. 2,5-disubstitued[1,2,4]triazolo[1,5-a]pyrimidinone heterocyclic core structure and its antimicrobial activity are reported to the literature for the first time in this study.