New Perspectives: Quinolones as Complexation Agents

Background: Quinolones are synthetic antibacterial agents, with a 4-oxo-1,4-dihydroquinolinic structure, which is based on the nalidixic acid model. The 4-oxo and 3-carboxyl groups confer quinolones excellent chelatation properties with metallic ions.
Aim: To highlight a few theories regarding the complexation phenomenon of quinolones.
Methods: Complexes with metallic ions have been characterized (stoichiometry, in vitro physical-chemicals properties, stability studies, and behavioral studies in different biological mediums).
Results: New availabilities have been identified: bioavailability of the complexed quinolones and formulation of new pharmaceutical products with a superior bioavailability and therapeutic effect; the antimicrobial activity of quinolone complexes; quinolone complexes as antitumor drugs with the aim of obtaining less toxic compounds; understanding the mechanism of action of quinolones, which is a challenge especially regarding their selectivity at the bacterial DNA level; development of new determination methods, based on the complexation of quinolones with metallic ions.
Conclusions: The 21st century may provide new useful therapeutic aspects on the basis of complexation between quinolones and metals.