Synthesis, characterization and antibacterial activity of Cu (II) and Zn (II) complexes of 5-aminobenzofuran-2-carboxylate Schiff base ligands

Abstract

The ever-increasing spread of bacterial infection with rising antibacterial drug resistance has become a matter of global concern in the modern times. Therefore, such serious infections leading to high mortality rate has necessitated the search for new classes of effective antibacterial agents with minimum toxicity. Herein, we report the synthesis and identification of a new class of benzofuran based Schiff ligands (6a-6e) and their Cu/Zn complexes (7a-7j) via sequential reactions starting with Salicylaldehyde. Compounds 6a, 7c and 7e exhibit activity in the low microgram range against M. tuberculosis, showing the minimum inhibitory concentrations (MICs) of 1.6 μg/mL. The compounds 6e and 7b also show interesting antibacterial activity against S. Aureus, E. coli and B. Subtilis with comparable area of inhibition of standard drugs under study. This research suggests that benzofuran based compounds can serve as a promising lead scaffold in developing new drugs to combat microbial infections.

Keywords

• biological activity
• benzofuran
• schiff base
• metal complex
• tuberculosis