Copper(II) complexes of the fluoroquinolone antimicrobial ciproffoxacin. Synthesis, X-ray structural characterization, and potentiometric study
ABSTRACT Reaction of the fluoroquinolone antimicrobial ciprofloxacin with copper(II) nitrate in the presence of 2,2'-bipyridine resulted in the isolation of the complex [Cu(cip)(bipy) (Cl)0.7(NO3)0.3] (NO3).2H2O. Reaction of an aqueous solution of ciprofloxacin.HCl and NaCl with CuCl2 at pH 5.0 resulted in the isolation of [Cu(cip)2]Cl2.11H2O. The complex [Cu(cip) (bipy)(Cl)0.7(NO3)0.3] (NO3).2H2O crystallizes in the monoclinic space group P2(1)/n, with a = 13.955(8), b = 14.280(8), c = 14.192(6) A, beta = 93.10(4) degrees, Z = 4 with R = 0.046. The selective broadening of resonances in the 13C NMR spectrum of ciprofloxacin by the addition of Cu2+(aq) was employed to probe metal ion binding sites in the ligand. The protonation constants of norfloxacin and ciprofloxacin, and the formation constants with copper(II), were determined by potentiometric titrations at 25 degrees C. The additions of ciprofloxacin to metal to form ML and ML2 complexes exhibit stepwise formation constants of log K1 6.2(1) and log K2 11.1(3), respectively.
- SourceAvailable from: Xueyuan Gu
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- "Me(CIP ± ) 2+ , Me(CIP ± ) 2 2+ , and Me(CIP − ·CIP ± ) + (Turel and Bukovec 1996; Wallis et al. 1996 "
ABSTRACT: Ciprofloxacin (CIP) can be strongly adsorbed by ferric oxides, but some influencing factors, such as multivalent cations and soil organic matter, have not been evaluated extensively. In this study, the interaction between CIP and four divalent metals (Ca, Cd, Cu, and Pb) was investigated using potentiometric titration and the results indicated that CIP can bind to the divalent metals in the following affinity order: Cu(II) > Pb(II) > Cd(II) > Ca(II). The effects of metals and fulvic acid (FA) on the adsorption behavior of CIP onto goethite surfaces were also examined using batch experiments. It was found that metal cations enhanced the CIP retention on goethite surfaces in the same order as the affinity order with CIP, indicating that metals likely increased CIP retention through cation bridging. FA was found to promote CIP sorption rather than compete with it, and the coexistence of FA and Cu(II) in the system exhibited an addictive effect with CIP sorption, indicating that they might influence the sorption separately under the studied loading condition. Taken together, our results suggested that the coexistence of divalent cations or soil organic matter will enhance CIP sorption on goethite surfaces, hence reducing its mobility and bioavailability in the environment.Environmental Science and Pollution Research 08/2014; 22(1). DOI:10.1007/s11356-014-3351-4 · 2.76 Impact Factor
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- "The solid formed was filtrated, washed with pre-cooling deionized water, and finally lyophilized. CIP(Cu)$ÂH 2 O and (CIP) 2 Cd$ÂH 2 O were prepared according to the procedures reported by Wallis et al. (1996) and López-Gresa et al. (2002), respectively. In brief, CIP was dissolved in deionized water and metallic chloride was added. "
ABSTRACT: Co-contamination of ligand-like antibiotics (e.g., tetracyclines and quinolones) and heavy metals prevails in the environment, and thus the complexation between them is involved in environmental risks of antibiotics. To understand toxicological significance of the complex, effects of metal coordination on antibiotics' toxicity were investigated. The complexation of two antibiotics, oxytetracycline and ciprofloxacin, with three heavy metals, copper, zinc, and cadmium, was verified by spectroscopic techniques. The antibiotics bound metals via multiple coordination sites and rendered a mixture of various complexation speciations. Toxicity analysis indicated that metal coordination did modify the toxicity of the antibiotics and that antibiotic, metal, and their complex acted primarily as concentration addition. Comparison of EC(50) values revealed that the complex commonly was highest toxic and predominately correlated in toxicity to the mixture. Finally, environmental scenario analysis demonstrated that ignoring complexation would improperly classify environmental risks of the antibiotics.Environmental Pollution 04/2012; 166:48-56. DOI:10.1016/j.envpol.2012.03.009 · 3.90 Impact Factor
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ABSTRACT: The survey reviews the data on the synthesis, structure and biological activity of fluoroquinolonecarboxylic acids metal chelates. The influence of metal and ligand nature as well as conditions of the synthesis on the polyhedron type is discussed. The data on interaction between fluoroquinolone metal complexes and DNA are explored.Russian Journal of General Chemistry 12/2010; 79(12):2753-2766. DOI:10.1134/S1070363209120342 · 0.42 Impact Factor