M. R. Chhasatia

Antibacterial and DNA interaction studies of zinc(II) complexes with quinolone family member, ciprofloxacin

DNA binding and cleavage characteristics of Zn(II) complexes have been investigated. The DNA interaction property of the complexes has been investigated using absorption spectra, viscosity measurements, as well as gel electrophoresis studies. Intrinsic binding constant (K(b)) has been estimated under similar set of experimental conditions. Absorption spectral study indicate that the Zn(II) complexes intercalate between the base pairs of the DNA tightly with intrinsic binding constant in the range of 1.0 x 10(4)-4.0 x 10(4)M(-1) in phosphate buffer. The proposed DNA binding mode supports the large enhancement in the relative viscosity of DNA on binding. The antimicrobial activity of all the ligands and metal complexes has been examined by minimum inhibitory concentration method (MIC).

DNA-interaction and in vitro antimicrobial studies of some mixed-ligand complexes of cobalt(II) with fluoroquinolone antibacterial agent ciprofloxacin and some neutral bidentate ligands.

Six new mixed-ligand complexes of Co(II) with ciprofloxacin (Cip) and neutral bidentate ligands have been synthesized and characterized. Binding and cleavage of DNA with the complex were investigated using spectroscopic method, viscosity measurements and gel electrophoresis techniques. Antibacterial activity has been assayed against two Gram((-ve)) and three Gram((+ve)) microorganisms using the doubling dilution technique.

Five-coordinated oxovanadium(IV) complexes derived from amino acids and ciprofloxacin: synthesis, spectral, antimicrobial, and DNA interaction approach.

Five-coordinated oxovanadium(IV) complexes with ciprofloxacin and various uninegative bidentate amino acids have been prepared. The structure of complexes has been investigated using spectral, physicochemical, mass spectroscopy, and elemental analyses. The antimicrobial activities (MIC) of the complexes, ligands, metal salt, and some standard drugs have been evaluated using the doubling dilution technique against Staphylococcus aureus, Bacillus subtilis, Serratia marcescens (gram-positive), and Pseudomonas aeruginosa, and Escherichia coli (gram-negative) bacteria. The result shows the significant increase in the antibacterial activity of the ligand, metal, and ciprofloxacin on complexation. The interaction of the complexes with pBR322 DNA has been investigated using spectroscopic, gel electrophoresis, and viscometric techniques. This shows that the complexes can bind to pBR322 DNA by the intercalative mode. The superoxide dismutase-like activity of the complexes has been determined.

In vitro bacteriostatic and DNA interaction studies of drug-based mixed-ligand complexes of cobalt(II)

The dinuclear cobalt(II) complexes with ciprofloxacin and bidentate ligands were synthesized and characterized using infrared spectra, electronic spectra, magnetic measurements, elemental analyses, thermal investigation, and mass spectroscopy. Here in we tried to increase an antibacterial activity of ciprofloxacin drug due to formation of mixed-ligand complexes. Synthesized compounds were found to be more potent compared to drugs, ligands, and metal salt against selective gram(+ve) and gram(−ve) organisms. Interaction of the complexes with nucleic acid (DNA) was investigated using spectroscopic technique, viscosity measurement, and gel electrophoresis and it was found that the complexes bind to DNA via intercalative mode.

Synthesis, characterization, in-vitro biocidal and nuclease activity of some coordination compounds

Complexes of Cu(II), Fe(II) and Fe(III) have been synthesized with 2-nitro-3,3′-benzylidene bis[4-hydroxycoumarin]/4-chloro-3,3′-benzylidene bis[4-hydroxycoumarin]/4-hydroxy-3,3′-benzylidene bis[4-hydroxycoumarin]. They have been characterized using 1H-NMR, 13C-NMR, IR spectra, electronic spectra, magnetic measurements, elemental analyses and screened for their in-vitro biocidal activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, and Serratia marcescens bacterial strains and for their in-vitro antifungal activity against Aspergillus niger, Aspergillus flavus and Lasiodiplodia theobromae. The metal complexes exhibit good activity against bacterial strains compared to parent compounds, but no significant antifungal activity against fungal strains. In-vitro nuclease activity has been carried out using agarose gel electrophoresis. The synthesized compounds show effective nuclease activity.

DNA interactions and promotion in antibacterial activities of ciprofloxacin drug due to formation of mixed-ligand complexes of oxovanadium(IV).

Mixed-ligand complexes of oxovanadium(IV) of the type [VOAL]·2H2O [where A = ciprofloxacin and L = uninegative bidentate ligands] have been synthesized and characterized using infrared spectra, electronic spectra, magnetic measurements, elemental analyses, thermal investigation, and mass spectroscopy. Here, we tried to increase an antibacterial activity of ciprofloxacin drug due to formation of mixed-ligand complexes. The complexes were found to be more potent compare to some standard drugs, ligands and metal salt against selective gram(+ve) and gram(−ve) organisms. Binding of the complexes with DNA have been investigated by spectroscopic absorption titration and viscometric techniques. The mixed-ligand complexes show good binding ability. The cleavage efficacy has been determined using gel electrophoresis method and complexes were found to be more active compared to parental ligands and metal salt.

DNA cleavage, binding and intercalation studies of drug-based oxovanadium(IV) complexes

The complexes of oxovanadium(IV) with ciprofloxacin and various uni-negative bidentate ligands have been prepared and their structure investigated using spectral, physicochemical and elemental analyses. The viscosity measurement suggest that the complexes bind to DNA by intercalation. The DNA binding efficacy was determined using absorption titration to obtain the binding constant (Kb). The DNA cleavage efficacy was determined using gel electrophoresis. The DNA binding and cleavage efficacy were increased in the complexes relative to the parental ligands and metal salts. Antibacterial activity has been assayed against two Gram( − ve) i.e. Escherichia coli, Pseudomonas aeruginosa and three Gram( + ve) Staphylococcus aureus, Bacillus subtilis, Serratia marcescens microorganisms using the doubling dilution technique. The results show a significant increase in antibacterial activity in the complexes compared with parental ligands and metal salts.

Coordination Polymeric Assemblies of some d‐Block Elements with Schiff Bases and its Characterization

A few coordination chain polymeric assemblies of the type [M(SB)(H2O)2]n [M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), H2SB1=1,1′‐dihydroxy‐2,2′‐(1‐isonitriloethylidyne ‐4‐nitrilomethylidenephenyl)diphenyl or H2SB2=1‐thio‐1′‐hydroxy‐2,2′‐(1‐isonitriloethylidyne‐4‐nitrilomethylidenephenyl)diphenyl have been investigated. Structural and spectroscopic properties have been studied on the basis of elemental analyses, infrared spectra, 1H‐NMR, 13C‐NMR, electronic spectra, magnetic measurements and thermogravimetric analyses. The Schiff bases act as binegative tetradentate ligands and bonding occur through the nitrogen and oxygen or sulfur atoms. An octahedral geometry has been assigned to all the prepared coordination polymers. The coordination polymers are insoluble in common organic solvents like benzene, acetone, ethyl acetate, methanol, ethanol, chloroform, dimethyl formamide and dimethyl sulphoxide.