Synthesis, Characterization and Antimicrobial Activity of Vanadium Tetracycline Metal Ion Complex

With increase in antimicrobial drug resistance, metal ion complexes are playing significant roles in the development of antimicrobial drugs. Vanadium complexes of the antibiotic tetracycline was synthesized through reaction of tetracycline and vanadium sulphate (VOSO₄) using ethanol as reagent. The produced vanadium tetracycline complex was characterized by UV-Vis absorption spectroscopy with a peak absorption at 450nm. Furthermore, the complex was found to be soluble in water but partially soluble in ethanol, with a melting point of 240ᴼC. The antibacterial activity of the vanadium tetracycline complex was tested against clinical isolates of Escherichia coli using the agar well diffusion assay. The bacteria were found to be sensitive to the complex at a concentration of 6.25mg/ml, producing a zone of inhibition of 19mm. A minimum inhibitory concentration (MIC) of 12.5mg/ml was determined to inhibit growth while a minimum bactericidal concentration (MBC) of 25mg/ml was shown to effectively kill the test organism. These results were more effective than the commercial tetracycline used as control, thus indicating the potential of this complex to be a possible candidate for the treatment of bacterial infections caused by multidrug resistant microorganisms.