Synthesis of novel menthol derivatives containing 1,2,3-triazole group and their in vitro antibacterial activities

New N-substituted alpha-aminonitrile derivatives from menthol were synthesized by consecutive succinic ester formation, propargylation, 1,3-dipolar Huisgen cycloaddition and Strecker reaction. The structures of the synthesized compounds were confirmed by diverse spectroscopic techniques including H-1-NMR, C-13-NMR, ESI-MS and IR. The novel synthesized compounds were evaluated for their in vitro antibacterial activities against Staphylococcus aureus as Gram-positive and Escherichia coli as Gram-negative bacteria. These compounds demonstrated a strong inhibitory effect against S. aureus with the minimum inhibitory concentration (MIC) values ranged from 32-128 mu g mL(-1). Derivatives 6a(2), 6b(1), 6b(4) and 6b(5) with a MIC value of 32 mu g mL(-1) exhibited the best inhibitory effects.