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

Abstract

New N-substituted ?-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 1HNMR, 13C-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 ?g mL-1. Derivatives 6a2, 6b1, 6b4, and 6b5 with a MIC value of 32 ?g mL-1 exhibited the best inhibitory effects.