Papers by debjani chakraborty
The reduction steps of ternary complexes of Cu(JI) with dipeptide, glycylglycine (gg) and amino a... more The reduction steps of ternary complexes of Cu(JI) with dipeptide, glycylglycine (gg) and amino acids ex-alanine (ala); tyrosine (tyr); and histidine and the amino acids ex-alanine (ala), tyrosine (tyr), phenylalanine (phe) and tryptophan (trp) have been studied by cyclic voltammetry in aqueous medium. The reduction proceeds through a one electron process resulting in the formation of copper(J) ternary complexes. The copper(J) dipeptide amino acid species are found to be unstable and undergo disproportionation yielding Cuo and Cu(JI) complex at the mercury electrode. The imidazole coordination of histidine in binary and ternary complexes stabilizes the Cu(J) species due to which there is no disproportionation and hence there is no formation oCCui) complex. This emphasises the significance of imidazole coordination in stabilizing Cu(I) state in biological redox processes.
Applied mathematics and computation, 2007
In this paper, we consider a continuous review inventory system where fuzziness and randomness ap... more In this paper, we consider a continuous review inventory system where fuzziness and randomness appear simultaneously into an optimization setting. Since demand plays an important role in such type of inventory systems, we develop a model in a mixed environment by ...
ABSTRACT Mixed ligand Cu(II) complexes of third generation fluoroquinolone antibacterial agents m... more ABSTRACT Mixed ligand Cu(II) complexes of third generation fluoroquinolone antibacterial agents moxifloxacin (MFL) and gatifloxacin (GFL) have been synthesized and characterized spectroscopically. The complexes have been found to bind DNA by intercalative mode and the DNA binding constants K-b and K-sv have been determined by absorption measurements and florescence quenching experiments respectively. The anti-proliferative and apoptosis inducing activity of the mixed ligand copper complexes against human lung carcinoma cells(A-549) was determined adopting MTT-assay, other specific staining techniques and DNA ladder. All the complexes have been shown to be cytotoxic towards A549 lung cancer cells. The complexes have been shown to bring about apoptosis of the cancerous cells.
Journal of Coordination Chemistry
Journal of Inorganic Biochemistry, 1991
The formation constant of the mixed ligand complexes of the type (CuAL) and (CUA_~L). where A ref... more The formation constant of the mixed ligand complexes of the type (CuAL) and (CUA_~L). where A refers to glycylglycine, glycyl-L-alanine, and glycyl-L-leucine; and L refers to indole acetic acid, indole propionic acid, and indole butyric acid. They were determined in 1: 1 (V/V) dioxan-water medium at 30°C and I = 0.2 M (NaCIO,), using SCOGS computer program. The astatistical stabilization of the ternary complexes has been attributed to intramolecular i*:+ogen bond formation between the two ligands .
Journal of the Iranian Chemical Society
Journal of Inorganic Biochemistry, 1990
The formation constants of the mixed ligand complexes of the type (CuAL), where A refers to glycy... more The formation constants of the mixed ligand complexes of the type (CuAL), where A refers to glycylglycine (A 1 ), glycyl-l-alanine (A 2 ), and glycyl-l-leucine (A 3 ) and L refers to α-alanine (L 1 ), phenylalanine (L 2 ), tryptophan (L 3 ), tyrosine (L 4 ), and l-dopa (L 5 ), were ...
Advances in Chemistry, 2014
A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed... more A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II). The ligands are coordinated to Cu(II) ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic.
Transition Metal Chemistry
Australian Journal of Chemistry, 2008
Anisotropic palladium and platinum nanoparticles were synthesized by reduction of the correspondi... more Anisotropic palladium and platinum nanoparticles were synthesized by reduction of the corresponding metal ions with hydrazine using polyacrylamide as a stabilizing agent in aqueous medium under microwave irradiation. The formation of particles was confirmed by UV-visible spectroscopy. The size and shape of the particles were determined using transmission electron microscopy. Rapid microwave heating resulted in 'star-shaped' palladium nanoparticles, but platinum nanoparticles were observed to be spherical with a distinctly visible 3-4 nm coating of polyacrylamide on their surface, which was not observed for the palladium particles. The Pt nanoparticles were used as a catalyst in the redox reaction.
Journal of the Chemical Society, Dalton Transactions, 1990
... Ternary complexes of substituted catechols and dipeptides with copper(II).Debjani Chakraborty... more ... Ternary complexes of substituted catechols and dipeptides with copper(II).Debjani Chakraborty and Pabitra K. Bhattacharya J. Chem. Soc., Dalton Trans., 1990, 3325-3327. DOI: 10.1039/DT9900003325 , Paper. ...
Journal of Photochemistry and Photobiology A: Chemistry, 2015
ABSTRACT Two different series of ruthenium complexes, ML3 and MLL′2 where M = Ru(III)/Ru(II), L =... more ABSTRACT Two different series of ruthenium complexes, ML3 and MLL′2 where M = Ru(III)/Ru(II), L = ferrocenyl amino acid mannich base conjugates and L′ = 1,10-phenanthroline have been synthesized and characterized by spectroscopic methods. These ferrocenyl ligands and their ruthenium complexes have been investigated for their interactions with DNA and BSA (bovine serum albumin) employing steady-state fluorescence quenching measurements, UV–vis spectroscopy and DNA viscosity measurements. High binding constants obtained from the DNA binding studies (Kb = 104 – 106 M−1) prompted the in-vitro cytotoxicity assay of complexes on A549 human lung carcinoma cells (employing MTT assay). The IC50 values (within the range of 46 μM–422 μM) obtained herein were found to be lower than those of the well known ruthenium complex NAMI-A currently under phase II clinical trials which has IC50 values in the range of 550 μM–750 μM for various cancer cell lines. Interaction of these complexes with A549 cells has been further scrutinized using acridine orange (AO)/ethidium bromide (EB) dual staining technique to indicate apoptosis as the mode of cell death.
Journal of Photochemistry and Photobiology A: Chemistry, 2017
Journal of Biomolecular Structure and Dynamics
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Papers by debjani chakraborty