SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITIES OF BIOINORGANIC COMPLEXES OF MOXIFLOXACIN

Background: The growth of different organisms is controlled by drug-metal complexes which are injurious to humans. Moxifloxacin is one of the fourth generation fluoroquinolone antibiotics which inhibits DNA gyrase (a type II topoisomerase and topoisomerase IV). A number of studies were conducted on the Moxifloxacin-metal complexes regarding their biological applications. In this study synthesis and characterization of three moxifloxacin- biometal complexes with Zn(I), Ni(VI) and Co(VIII) was done and their antibacterial and antioxidant effects were studied. Methods: Moxifloxacin- zinc chloride, nickel chloride and cobalt chloride were synthesized by mixing solutions of zinc chloride, nickel chloride and cobalt chloride with the ethanolic solution of Moxifloxacin. These metal complexes were characterized by physio-chemical techniques such as FTIR, 1 H- NMR, and UV-Vis. To study the antibacterial effects of Moxifloxacin-metal complexes agar well diffusion method was used. Antioxidant activity was determined by DPPH free radical scavenging method. Results: The structural assessment of these complexes has been carried out based on physio- chemical and spectroscopic methods. The FTIR spectra and 1H NMR clearly showed that metal-moxifloxacin complexes are formed due to change in their carboxyl stretching band in IR, H-2 and H-5 peak position in 1H NMR. Further, Zn(I), Ni(VI) and Co(VIII), moxifloxacin metal complexes have shown significant antibacterial activity against gram-positive and gram-negative bacteria. Conclusions: The spectral and analytical results clearly confirmed the coordination chemistry of Zn(I), Ni(VI) and Co(VIII). The moxifloxacin?Ni(VI) and Co(VIII) metal complexes showed high antibacterial activity compared to moxifloxacin--Zn(I). The antibacterial activity indicates that metal complexes have higher biological activity than parent drug (moxifloxacin).