Mononuclear Metal Complexes of Moxifloxacin with Antacids: Synthesis, Spectroscopic Characterization, and Antimicrobial Activities

Mononuclear metal complexes of 1-cyclopropyl-7-[(S,S)-2,8-diazabicyclo[4.3.0]non-8-yl]-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinoline carboxylic acid (moxifloxacin) with commonly used antacids metal ions have been prepared and studied by physicochemical, elemental analysis and spectroscopic techniques (IR and 1H NMR spectroscopy). In all synthesized metal complexes, moxifloxacin acted as a bidentate deprotonated ligand that bound to the metal through the carbonyl oxygen and one carboxylate oxygen atoms. The complexes were screened against 11 Gram-positive and Gram-negative organisms and also screened against 6 fungi, where moxifloxacin was used as standard. It has been concluded that some of these complexes showed in vitro growth inhibitory activities comparable with or higher than the parent drug.