Synthesis and antimicrobial activity of some novel 1,2-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines bearing amino acid moiety

A new series of [1,2,4]-triazole bearing amino acid derivatives 2a-d-9a-d were synthesized under green chemistry conditions via multicomponent reaction using lemon juice as an acidic catalyst. The obtained compounds were characterized by different spectral and elemental analyses. The obtained candidates showed promising antibacterial activity against some standard bacteria and multidrug resistant (MDR) clinical isolates. In contrast to the reference drugs cephalothin and chloramphenicol, the tested compounds showed substantial better MIC values towards the tested MDR strains. The most active compounds 3c, 8a and 9d against MDR bacteria were tested for MBC and MIC index, the results indicted the bacteriostatic activity of these compounds. The most active compounds 2c, 2d, 3c, 8a, 8b, 9a, 9b, 9c and 9d showed a high selectivity index towards antimicrobial activity against K. pneumoniae and MRSA1 compared to mammalian cells, suggesting a good safety profile.

Automated summary

A series of novel [1,2,4]-triazole derivatives bearing amino acids were synthesized using lemon juice as an acidic catalyst under green chemistry conditions. These compounds showed promising antibacterial activity against standard bacteria and multidrug resistant strains, with better MIC values compared to reference drugs. Some compounds exhibited bacteriostatic activity and high selectivity towards antimicrobial activity against specific bacteria, indicating a good safety profile.