Synthesis of Levofloxacin Derivatives with some Amines and their Complexes with Copper(II) Salts and Evaluation of their Biological Activity

Abstract

Levofloxacin belongs to the fluoroquinolone family; it is a potent broad-spectrum bactericidal agent. The pharmacophore required for significant antibacterial activity is the C-3 carboxylic acid group and the 4-pyridine ring with the C-4 carbonyl group, into which binding to the DNA bases occur. In this work, we tried to show that by masking the carboxyl group through amide formation using certain amines to form levofloxacin carboxamides, an interesting activity is kept. Levofloxacin carboxamides on the C-3 group were prepared, followed by the formation of their copper complexes. The target compounds were characterized by FT-IR, elemental analysis. The antimicrobial activity of the target compounds was evaluated and showed satisfactory results compared with levofloxacin. This has indicated that the presence of the carbonyl of C-3 carboxyl moiety is not essential, as levofloxacin carboxamides showed interesting copper complexes indicating that they retain the activity of levofloxacin, since its activity depends on binding to DNA gyrase via magnesium binding.