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.