Synthesis and antibacterial activities of N-substituted-glycinyl 1H-1,2,3-triazolyl oxazolidinones.

A series of 1H-1,2,3-triazolyl piperazino oxazolidinone analogs with optionally varied glycinyl substitutions were synthesized and their antibacterial activity assessed against a panel of susceptible and resistant Gram-positive and selected Gram-negative bacteria including clinical isolates. The N-aroyl- and N-heteroaroyl-glycinyl (MIC: 0.06-4 μg/ml) derivatives were more potent than the N-acylglycinyl (2-8 μg/ml) derivatives against all Gram-positive bacteria tested. Nitro substitution on aryl and heteroaryl rings significantly enhanced activity against Gram-positive bacteria, as noted with the 3,5-dinitrobenzoyl (6m and 6n) and 5-nitro-2-furoyl (6u and 6v) derivatives with MIC ranges of and 0.25-0.5 and 0.06-0.5 μg/ml, respectively. These nitro analogs also showed more potent extended activity against Moraxella catarrhalis, with MICs ranges of 0.25-1 μg/ml, compared to linezolid (MIC: 8 μg/ml). Hence, the presence of the N-aroyl and/or N-heteroaroyl glycinyl structural motifs as spacer group could significantly enhance the antibacterial activities of 1H-1,2,3-triazolyl oxazolidinone class of compounds.