Tamilnadu, India
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Raman N.,VHNSN College | Selvaganapathy M.,VHNSN College
Inorganic Chemistry Communications | Year: 2013

Three novel mixed-ligand complexes using pyrazolone derivative (4-chloro-benzylidene-4-aminoantipyrine) as primary ligand and l-methionine as co-ligand, were synthesized and characterized by physico-chemical analytical techniques. The DNA interaction of these complexes was investigated by electronic absorption spectroscopy, viscosity, cyclic voltammetry and gel electrophoresis measurements. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. © 2013 Elsevier B.V.


Arun T.R.,VHNSN College | Raman N.,VHNSN College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

This work focuses the synthesis and characterization of few novel mixed ligand Schiff base metal complexes and their biological activities. For deriving the structural aspects, spectral techniques such as FT-IR, UV-Vis., 1H NMR, Raman, EPR and the physicochemical characterizations including elemental analysis, molar conductance and magnetic susceptibility method have been involved. All the complexes adopt square planar geometry. DNA binding ability of these complexes has been explored using diverse techniques viz. UV-Vis. absorption, fluorescence spectroscopy, viscometry and cyclic voltammetry. These studies prove that CT-DNA binding of the complexes follows the intercalation mode. Comparative DNA oxidative cleavage ability of the complexes has been done under ultraviolet photo radiation on pUC19 DNA. In addition, the biocidal action of the complexes has been investigated against few pathogenic bacteria and fungi by disc diffusion method. Importantly, the amylase inhibition activity of Cu(II) complex has been explored. The amylase inhibition property has been found to be increased upon increasing the complex concentration. © 2014 Elsevier B.V. All rights reserved.


Raman N.,VHNSN College | Pravin N.,VHNSN College
European Journal of Medicinal Chemistry | Year: 2014

Few novel Cu(II) and Zn(II) oxali-platin type complexes of stoichiometry [ML(ox)] where, L is a Knoevenagel ligand and ox is oxalic acid, have been explored. They are well characterized by spectroanalytical methods. The binding and cleavage propensity of these complexes on DNA and their cytotoxic effect in tumor cells have been investigated. They bind to DNA preferentially by intercalation and cleave the strands under mild reaction conditions even in the absence of external cofactors. However, in H2O2 medium they exhibit better efficacy in the nuclease reaction process by initiating DNA cleavage in an oxidative pattern. Complex 1 shows higher in vitro cytotoxic property against HeLa/EAC cells comparing to other complexes and the standards (cisplatin/5-FU). Moreover, the in vivo antitumor efficacy of copper complexes against EAC tumor model reveals that they are non-toxic to normal cells (lymphocytes). Among the copper complexes, complex 1 reveals excellent antitumor activity. © 2014 Elsevier Masson SAS. All rights reserved.


Pravin N.,VHNSN College | Raman N.,VHNSN College
European Journal of Medicinal Chemistry | Year: 2014

A series of carboplatin type Cu(II) and Zn(II) metalloinsertors (1-8) having β-diketone analogues and biologically significant cyclobutane-1,1-dicarboxylic acid have been synthesized and characterized by spectral and analytical methods. The binding and cleavage propensity of these metalloinsertors on DNA and their cytotoxic effects in live cells have been explored. From the gel electrophoresis study, it is observed that the complexes 1-8 cleave pBR322 DNA via a hydrolytic mechanism induced by hydroxyl radical scavengers, DMSO and EtOH as the reactive oxygen species (ROS). In vivo antitumor efficacy has been studied on EAC tumor bearing mice which is assessed by mean survival time, effect on hematological parameters and solid tumor volume. The results strongly support that complex 1 shows potent antitumor effect against EAC and higher than the standard drug carboplatin. Moreover, the cytotoxicity of the complexes, screened on a panel of human cancerous cell lines viz., human cervical cancer cells (HeLa), human breast adenocarcinoma cells (MCF-7), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines, reveals that complex 1 exhibits a better anticancer activity than other complexes and standards. © 2014 Elsevier Masson SAS. All rights reserved.


Raman N.,VHNSN College | Sobha S.,VHNSN College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

Few novel 4-aminoantipyrine derived Schiff bases and their metal complexes were synthesized and characterized. Their structural features and other properties were deduced from the elemental analysis, magnetic susceptibility and molar conductivity as well as from mass, IR, UV-vis, 1H NMR and EPR spectral studies. The binding of the complexes with CT-DNA was analyzed by electronic absorption spectroscopy, viscosity measurement, and cyclic voltammetry. The interaction of the metal complexes with DNA was also studied by molecular modeling with special reference to docking. The experimental and docking results revealed that the complexes have the ability of interaction with DNA of minor groove binding mode. The intrinsic binding constants (K b) of the complexes with CT-DNA were found out which show that they are minor groove binders. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pUC19 DNA in the presence of AH 2 (ascorbic acid). Moreover, the oxidative cleavage studies using distamycin revealed the minor groove binding for the newly synthesized 4-aminoantipyrine derived Schiff bases and their metal complexes. Evaluation of antibacterial activity of the complexes against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Klebsiella pneumoniae exhibited that the complexes have potent biocidal activity than the free ligands. © 2011 Elsevier B.V. All rights reserved.


Raman N.,VHNSN College | Mahalakshmi R.,VHNSN College
Inorganic Chemistry Communications | Year: 2014

The paper presents the synthesis of complex combinations of Cu(II), Zn(II) and Ni(II) with Schiff bases obtained by the condensation reaction of diphenylglyoxal with 1-amino-4-nitrobenzene (L1)/1-amino-4- chlorobenzene (L2)/p-anisidine (L3) as the main ligand and 1,10-phenanthroline as the co-ligand respectively. The characterization of newly formed complexes has been done by spectral and molar conductivity studies. The bioefficacy of the ligands and their complexes have been examined against the growth of bacteria and fungi in vitro to evaluate their antimicrobial potential. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. X-ray powder diffraction illustrates that the complexes have crystalline nature. The effect of the metal complexes on DNA is carried out by pUC19 DNA agarose gel electrophoresis at 50 V for 2 h. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. © 2013 Elsevier B.V. All rights reserved.


Selvaganapathy M.,VHNSN College | Raman N.,VHNSN College
Inorganic Chemistry Communications | Year: 2012

A new family of tryptophan based mixed-ligand complexes has been synthesized and characterized. DNA (Calf thymus) binding properties of the complexes have been explored by UV-vis, viscosity measurements and cyclic voltammetry. All the experimental evidence suggest that the ancillary ligand 2,2′-bipyridine influences the intercalative binding of these complexes to CT DNA. The DNA cleavage efficiencies of these complexes with pBR322 DNA were investigated by gel electrophoresis. The complexes were found to promote the cleavage of pBR322 DNA from the supercoiled form I to the open circular form II in the presence of an oxidizing agent (H 2O 2). Microbial property of these complexes as antibacterial agents has been investigated against Gram-negative and Gram-positive bacteria. © 2012 Elsevier B.V. All rights reserved.


Raman N.,VHNSN College | Sobha S.,VHNSN College
Inorganic Chemistry Communications | Year: 2012

A novel 4-aminoantipyrine derived Schiff base and its four mixed ligand complexes have been synthesized and characterized. The binding properties of metal complexes with DNA have been investigated by electronic absorption spectra and viscosity measurements showing that the complexes have the ability of interaction with DNA by intercalative mode. The effect of the metal complexes on DNA was carried out by pUC19 DNA agarose gel electrophoresis at 50 V for 2 h. The damage effect of the added ascorbic acid into the medium is dependent on the free radicals produced from oxidation of ascorbic acid by molecular oxygen and this damage is considered to be reduced by the metal complexes. © 2011 Elsevier B.V. All rights reserved.


Kathirvalavakumar T.,VHNSN College | Ponmalar E.,SFR College for women
International Journal of Machine Learning and Cybernetics | Year: 2013

The proposed work is hybridizing self organizing map (SOM) and wavelet transform for performing image compression. The novelty in this work is applying discrete wavelet transform (DWT) on the code vector obtained from SOM after vector quantization and storing only the approximation coefficients along with the index values of the SOM. The experimental results of the proposed method show better compression and better peak signal to noise ratio (PSNR) value of the decompressed image. © 2012 Springer-Verlag.


Pravin N.,VHNSN College | Raman N.,VHNSN College
Inorganic Chemistry Communications | Year: 2013

Four novel DNA metalloinsertors having imino-oxalato mixed-ligands, of the composition [ML(ox)]Cl2 (where M = Cu(II), Co(II), Ni(II) and Zn(II); ox = C2O4 2 - and L = N,N′-bis(4- chlorobenzylidene)benzene-1,2-diamine) were synthesized. They were fully characterized by microanalytical data, magnetic susceptibility values, molar conductivity measurements, UV-vis, IR, 1H NMR, 13C NMR and EPR techniques. Their geometry was explored and found to have square-planar geometry. Electronic absorption spectroscopy, cyclic voltammetry and viscosity measurements indicate that these mixed-ligand complexes strongly bind to calf thymus DNA, presumably via an intercalation mechanism. Further, DNA cleavage efficacy of these complexes was investigated by gel electrophoresis. The complexes were found to promote the cleavage of pBR322 DNA in the presence of the reluctant, ascorbic acid. The ligand (L) and the mixed-ligand complexes were tested for their efficiency towards antimicrobial activity and their MIC data reveal that all the complexes have strong activity in comparison to the free ligand and standard drugs, ciprofloxacin and fluconazole. © 2013 Elsevier B.V.

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