Development of 8-benzyloxy-substituted quinoline ethers and evaluation of their antimicrobial activities

A series of 8-benzyloxy-substituted quinoline ethers ( 2a – n ) compounds were synthesized. All synthesized compounds were screened in vitro for their preliminary antimicrobial activities against two Gram-negative bacteria ( Pseudomonas aeruginosa and Escherichia coli ), two Gram-positive bacteria ( Staphylococcus aureus and Staphylococcus epidermidis ), and a fungal species ( Aspergillus niger ). Among all synthesized compounds, compound 2e showed a significant growth inhibitory activity with MIC value 3.125 μg/mL which was comparable to 8-hydroxyquinoline (2.5 μg/mL) and terbinafine (1.25 μg/mL) against A. niger .