Abstract

FLUOROQUINOLONE ANTIBIOTIC (ENROFLOXACIN) METAL COMPLEXES: SYNTHESIS, SPECTROSCOPIC AND IN VITRO ANTIMICROBIAL SCREENING PROPERTIES

Nadia E.A. El-Gamel*, M.A.Zayed

Abstract

Complexes of the antibiotic gyrase inhibitor enrofloxacin (HL1) with the transition metals Cu (II) (1), Mn (II) (2), Cr (III) (3), and Fe (III) (4) and in a mixed complex with dl-alanine (H2L2) with Cu (II) (5), Mn (II) (6), Cr (III) (7), and Fe (III) (8) were synthesized and their antibacterial activity (Staphylococcus aureus, Escherichia coli) and antifungal potential (Aspergillus flavus and candida albicans) was investigated in vitro. The complexes were characterized with elemental analysis, IR-and UV-Vis spectroscopy. Geometry and structural properties of the complexes were deduced from the magnetic susceptibility, measurements of the molar conductivity and from simultaneous measurements of thermal mass loss (TG) and differential thermal analysis (DTA). All complexes form chelates with planar (1) or distorted octahedral (2) - (8) geometry as indicated by spectroscopic measurements and calculations of the molar magnetic susceptibility m. Antibiotic in vitro assay screening showed a significant antibacterial and anti-fungal activity for the complexes Cu (II) (5) and Mn (II) (6), much higher compared with the other complexes and the pure enrofloxacin.

Keywords: Enrofloxacin, metal complexes, spectroscopic studies, simultaneous thermal analysis (TG/DTA), antimicrobial activity.