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

Abstract

New N-substituted α-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 μg mL-1. Derivatives 6a2, 6b1, 6b4 and 6b5 with a MIC value of 32 μg mL-1 exhibited the best inhibitory effects.

Keywords

• click reaction
• strecker synthesis
• α-aminonitrile
• huisgen reaction