Publications by authors named "V M Manikandamathavan"

8 Publications

Chromium-catechin complex, synthesis and toxicity check using bacterial models.

Heliyon 2020 Aug 6;6(8):e04563. Epub 2020 Aug 6.

Chemical Laboratory, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai 600 020, India.

Chromium-catechin complex was synthesized by reacting [Cr(HO)] (hexa-aqua) with catechin as a ligand. Toxicity studies were carried out for the complex using bacterial models for safer application of this complex in the future as a drug. Chromium-catechin complex was characterized using ESI Mass spectrometry, electronic spectroscopy, FT-IR spectroscopy and cyclic voltammetry. The complex was found mildly inhibitory towards with the mode of action being oxidative damage, targeting cell membrane. The complex was supportive towards , which was evident from the growth profile and inhibition studies. SEM analysis supported the results of membrane integrity studies, where the bacterial liposomes upon treatment with the complex revealed slight morphological changes in the case of , without any change in the case of . The toxicity studies on chromium-catechin complex using bacterial model saves time, as well as resources by providing quick and reliable results, which could ease up the work to be done in future with higher group of organisms like animal model. Therefore, in the future, this complex can be used as an antidiabetic drug after performing toxicity studies with animal model.
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http://dx.doi.org/10.1016/j.heliyon.2020.e04563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7415841PMC
August 2020

Novel mononuclear Cu (II) terpyridine complexes: Impact of fused ring thiophene and thiazole head groups towards DNA/BSA interaction, cleavage and antiproliferative activity on HepG2 and triple negative CAL-51 cell line.

Eur J Med Chem 2017 Jul 15;135:434-446. Epub 2017 Apr 15.

Chemical Laboratory, Central Leather Research Institute, Council of Scientific Industrial Research, Adyar, Chennai, India. Electronic address:

Two mononuclear copper (II) terpyridine complexes namely, [Cu(Btptpy) (ClO)](ClO) 1, and [Cu(Bttpy) (ClO)](ClO) 2, (Btptpy (L) = 4'-(Benzothiophene)-2,2':6',2″-terpyridine, Bttpy (L) = 4'-(Benzylthiazolyl)-2,2':6',2″-terpyridine) have been synthesized and characterized. Single crystal X-ray diffraction shows that, both ligands belong to monoclinic crystal system with space group P2/c (L) and P2/n (L). Absorption spectral titration, DNA melting study, circular dichroism and viscosity measurement reveal that, complex 1 and 2 bind with DNA through intercalation. In addition, interaction between the two copper (II) complexes and bovine serum albumin (BSA) has been studied by fluorescence titration, circular dichroism and their protease activity has been investigated using SDS-PAGE gel electrophoresis. Agarose (AGE) and SDS-PAGE gel electrophoresis reveals both complexes have good nucleolytic and proteolytic property in the presence of additive hydrogen peroxide. Both complexes shows remarkable cytotoxic property against triple negative CAL-51 human breast cancer cell line and hepatocellular carcinoma (HepG2) cancer cell lines and bears very less cytotoxicity towards liver normal cell line (Changs). DCF-DA and TBRAS assay also supported that complex 1 and 2 induces elevated level of reactive oxygen species (ROS) and oxidative stress in cancer cells than normal cell line. Furthermore, FACS analysis confirms complex 1 and 2 brings apoptosis by growth phase cell cycle arrest.
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http://dx.doi.org/10.1016/j.ejmech.2017.04.030DOI Listing
July 2017

Interactions of Ru(II) polypyridyl complexes with DNA mismatches and abasic sites.

Dalton Trans 2015 May;44(19):9044-51

Biophysics Laboratory, CSIR-Central Leather Research Institute, Adyar, Chennai 600 020, India.

Polypyridyl based ruthenium(II) complexes, [Ru(bpy)2(furphen)](PF6)2 (1) and [Ru(bpy)2(imiphen)](PF6)2 (2) {furphen: 2-(furan-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline and imiphen: 2-(1H-imidazol-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline} were synthesized and characterized by ESI-MS, NMR, UV-Visible and fluorescence spectroscopic techniques. The interaction of Ru(II) complexes with calf-thymus DNA (CT DNA) as well as oligonucleotides containing mismatches and abasic sites was studied along with unmodified control DNA. Based on absorption titration studies, binding constants (Kb) for the interaction of complexes 1 and 2 with DNA were found to be 6.7 ± 0.2 × 10(3) and 4.9 ± 0.2 × 10(4) M(-1), respectively. Hydrodynamic studies revealed weak interactions between the two complexes and CT-DNA. Luminescence studies revealed that both the complexes exhibit a five-fold increase in emission upon addition of CT-DNA. The integrated emission intensity of complexes 1 and 2 with CC mismatch oligonucleotides was 1.5 and 1.2 fold higher than that of control GC match oligonucleotides, respectively. Both the complexes did not show any specificity towards abasic or other mismatch sites except for CC mismatch. The results from this study provide an insight into the requirements of ligand shape in recognising DNA mutations such as mismatch and selectivity between DNA mismatches.
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http://dx.doi.org/10.1039/c5dt00807gDOI Listing
May 2015

DNA/protein interaction and cytotoxic activity of imidazole terpyridine derived Cu(II)/Zn(II) metal complexes.

Dalton Trans 2014 Sep;43(34):13018-31

Chemical Laboratory, Central Leather Research Institute, Council of Scientific and Industrial Research, Adyar, Chennai 600 020, India.

Two imidazole terpyridine (itpy) based complexes, [Cu(itpy)(OAc)(H2O)]NO3·H2O (1) and [Zn(itpy)(OAc)]OAc (2) have been synthesised and characterized. The crystal structure of complex 1 shows distorted octahedral geometry with an anti-parallel stacking arrangement. The interactions of the two complexes with Calf thymus DNA (ctDNA) have been studied using absorption titration and circular dichroism. Complex 1 shows coordinate binding to DNA bases, and complex 2 shows an intercalative mode of binding with DNA. Complex 1 cleaves the DNA via an oxidative pathway in the presence of additives, because of the presence of a redox active copper(II) centre. However, complex 2 cleaves DNA hydrolytically. Interactions of the two complexes with bovine serum albumin have been studied using fluorescence quenching and circular dichroism experiments. Circular dichroic analysis reveals that both the complexes strongly influence the secondary structure of the protein. Fluorescence quenching experiments indicate that there are different binding sites for complexes 1 and 2 on the protein. Furthermore, the complexes show potential cytotoxicity towards the A549 lung cancer cell line. Both the complexes have been found to induce apoptosis.
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http://dx.doi.org/10.1039/c4dt01378fDOI Listing
September 2014

DNA binding and cytotoxicity of copper (II) imidazole terpyridine complexes: role of oxyanion, hydrogen bonding and π-π interaction.

Eur J Med Chem 2013 Oct 14;68:244-52. Epub 2013 Aug 14.

Chemical Laboratory, Central Leather Research Institute, Council of Scientific Industrial Research, Adyar, Chennai 600 020, India.

Mononuclear complexes [Cu(Itpy)X(H2O)]X (Itpy--imidazole terpyridine, X--NO3 1 and X--ClO4 2) have been synthesized and characterized. Single crystal X-ray diffraction of complex 1 shows distorted octahedral geometry around the copper (II) ion. Presence of multiple hydrogen bonding network in the molecule results in anti-parallel stacking of the molecule. Both the complexes show dual mode of binding to DNA. Both the complexes have been found to bring about DNA cleavage in the presence of H2O2 and show potent cytotoxicity towards lung carcinoma cell line. The ability of the two complexes to induce apoptosis has been investigated by using combination of nuclear stains. FACS analysis shows that both the complexes bring about cell cycle arrest at 2.5 μM concentration.
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http://dx.doi.org/10.1016/j.ejmech.2013.07.051DOI Listing
October 2013
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