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Rengan Ramesh - One of the best experts on this subject based on the ideXlab platform.
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synthesis and structure of nickel ii Thiocarboxamide complexes effect of ligand substitutions on dna protein binding antioxidant and cytotoxicity
RSC Advances, 2015Co-Authors: Ramasamy Raj Kumar, Mohamed Kasim Mohamed Subarkhan, Rengan RameshAbstract:Four low spin d8 nickel(II) square planar complexes with general formula [Ni(L)2] (where L = monobasic N, S bidentate Thiocarboxamides) have been synthesized from the reaction of Ni(OAc)2·4H2O with 2 equivalent of Thiocarboxamide ligands in ethanol. The complexes have been fully characterized by analytical, spectral (FT-IR, UV-Vis, 1H and 13C NMR) and single crystal X-ray methods. Molecular structure of one of the complexes indicates a mono anionic bidendate coordination of Thiocarboxamide ligands to the nickel via pyridine nitrogen and thiolate sulphur and reveal a square planar geometry. The binding interaction of nickel(II) Thiocarboxamide complexes with calf-thymus DNA (CT-DNA) was studied by electronic and emission spectroscopic methods revealed that complexes 1–4 could interact with CT-DNA via intercalation mode. DNA cleavage experiment shows that all the complexes cleave pUC19 supercoiled DNA in the presence of an activator like H2O2. The CD spectral study shows that binding of the complexes to DNA does not lead to any significant changes in the conformation of CT-DNA. Further, the protein binding ability of the nickel(II) Thiocarboxamide complexes with the BSA was investigated by UV-Vis, fluorescence and synchronous fluorescence methods and a static quenching mechanism was observed for their interaction with BSA. The free radical scavenging ability of all the complexes was evaluated by in vitro antioxidant assays involving DPPH radical, hydroxyl radical and nitric oxide radical and was found to be excellent. Moreover, the efficiency of complexes 1–4 to arrest the growth of HeLa and MG-63 cell lines has been studied along with the cell viability test against the non-cancerous cells NIH-3T3 under in vitro condition. Complex 3 was found to be the highest anticancer activity among the nickel complexes.
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Synthesis and structure of nickel(ii) Thiocarboxamide complexes: effect of ligand substitutions on DNA/protein binding, antioxidant and cytotoxicity
RSC Advances, 2015Co-Authors: Ramasamy Raj Kumar, Mohamed Kasim Mohamed Subarkhan, Rengan RameshAbstract:Four low spin d8 nickel(II) square planar complexes with general formula [Ni(L)2] (where L = monobasic N, S bidentate Thiocarboxamides) have been synthesized from the reaction of Ni(OAc)2·4H2O with 2 equivalent of Thiocarboxamide ligands in ethanol. The complexes have been fully characterized by analytical, spectral (FT-IR, UV-Vis, 1H and 13C NMR) and single crystal X-ray methods. Molecular structure of one of the complexes indicates a mono anionic bidendate coordination of Thiocarboxamide ligands to the nickel via pyridine nitrogen and thiolate sulphur and reveal a square planar geometry. The binding interaction of nickel(II) Thiocarboxamide complexes with calf-thymus DNA (CT-DNA) was studied by electronic and emission spectroscopic methods revealed that complexes 1–4 could interact with CT-DNA via intercalation mode. DNA cleavage experiment shows that all the complexes cleave pUC19 supercoiled DNA in the presence of an activator like H2O2. The CD spectral study shows that binding of the complexes to DNA does not lead to any significant changes in the conformation of CT-DNA. Further, the protein binding ability of the nickel(II) Thiocarboxamide complexes with the BSA was investigated by UV-Vis, fluorescence and synchronous fluorescence methods and a static quenching mechanism was observed for their interaction with BSA. The free radical scavenging ability of all the complexes was evaluated by in vitro antioxidant assays involving DPPH radical, hydroxyl radical and nitric oxide radical and was found to be excellent. Moreover, the efficiency of complexes 1–4 to arrest the growth of HeLa and MG-63 cell lines has been studied along with the cell viability test against the non-cancerous cells NIH-3T3 under in vitro condition. Complex 3 was found to be the highest anticancer activity among the nickel complexes.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
Organometallics, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium (II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)(2)(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO-(AsPh3)(3)] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde.
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dna protein interaction and cytotoxicity of palladium ii complexes of Thiocarboxamide ligands
Inorganica Chimica Acta, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Nallasamy Dharmaraj, Yu LiuAbstract:Four planar palladium(II) complexes with general formula [Pd(Cl)(L)(PPh3)] (HL = N-substituted pyridine-2- Thiocarboxamide) have been synthesized and characterized by analytical, spectral (IR, UV-Vis and H-1, C-13 and P-31 NMR) and single crystal X-ray methods. Crystal structure of all the complexes indicated a mono negative bidentate coordination of Thiocarboxamide ligands to the palladium center via pyridine nitrogen and thiol sulfur and reveals a square planar geometry. The interaction of palladium(II) Thiocarboxamide complexes with calf thymus DNA (CT-DNA) studied by absorption and emission spectroscopic methods revealed that complexes 5-8 could interact with CT-DNA through intercalation. Further, the interaction of the palladium complexes with bovine serum albumin (BSA) was investigated using UV-Vis, fluorescence and synchronous fluorescence methods. The tryptophan and tyrosine residues in BSA as model protein was quenched by the complexes in a static quenching process. The radical scavenging ability of all the complexes was accessed by in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical and ABTS radicals and was found to be excellent. Further, the anti-cancer activity of complexes 5-8 against HeLa, MCF-7 and NIH-3T3 cell line has been studied. Though the complexes 5, 6 and 8 showed more potent anticancer activity than cisplatin, complex 5 was found to be superior. (C) 2014 Elsevier B.V. All rights reserved.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium(II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)2(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO(AsPh3)3] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV–vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde
A. V. Koval’skaya - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Guanidine Derivatives of Methylcytisine
Chemistry of Natural Compounds, 2019Co-Authors: P. R. Petrova, A. V. Koval’skaya, Alexander N. Lobov, Inna P. TsypyshevaAbstract:Guanidine derivatives of the quinolizidine alkaloid methylcytisine were synthesized by converting its 9-amino-derivative into the corresponding Thiocarboxamide using phenylisothiocyanate and then into trisubstituted guanidines using HgCl2 in the presence of aromatic amines.
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Synthesis of Methylcytisine 9-Thiocarboxamides
Chemistry of Natural Compounds, 2019Co-Authors: P. R. Petrova, A. V. Koval’skaya, Alexander N. Lobov, Inna P. TsypyshevaAbstract:9-Carboxamide derivatives of the quinolizidine alkaloid methylcytisine were synthesized. The synthetic pathway included nitration-reduction according to the literature that resulted in 9-amination of the 2-pyridone core of the starting alkaloid. The obtained 9-amino derivative was converted by CS_2 in Py in the presence of dicyclohexylcarbodiimide (DCC) into the corresponding isothiocyanate. The synthesized 9-isothio derivative was reacted with primary and secondary amines. The yields of the obtained 9-Thiocarboxamide methylcytisine derivatives were 80–98%. The structures of the synthesized compounds were established using elemental analyses and IR, PMR, ^13C NMR, and ^15N NMR spectroscopy.
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Molecular and crystal structure of (1R,5S)-8-oxo-1,5,6,8-tetrahydro-2H-1,5-methanopyrido[1,2-a][1,5]diazocine-3(4H)-carboxamide and (1R,5S)-8-OXO-1,5,6,8-tetrahydro-2H-1,5-methanopyrido[1,2-a][1,5]diazocine-3(4H)-Thiocarboxamide
Journal of Structural Chemistry, 2015Co-Authors: K. Yu. Suponitskii, Inna P. Tsypysheva, A. V. Koval’skayaAbstract:The molecular and crystal structure of (1 R ,5 S )-8-oxo-1,5,6,8-tetrahydro-2 H -1,5-methanopyrido[1,2- a ][1,5]diazocine-3(4 H )-carboxamide and (1 R ,5 S )-8-oxo-1,5,6,8-tetrahydro-2 H -1,5-methanopyrido[1,2- a ][1,5]diazocine-3(4 H )-Thiocarboxamide are determined.
Yu Liu - One of the best experts on this subject based on the ideXlab platform.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
Organometallics, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium (II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)(2)(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO-(AsPh3)(3)] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde.
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dna protein interaction and cytotoxicity of palladium ii complexes of Thiocarboxamide ligands
Inorganica Chimica Acta, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Nallasamy Dharmaraj, Yu LiuAbstract:Four planar palladium(II) complexes with general formula [Pd(Cl)(L)(PPh3)] (HL = N-substituted pyridine-2- Thiocarboxamide) have been synthesized and characterized by analytical, spectral (IR, UV-Vis and H-1, C-13 and P-31 NMR) and single crystal X-ray methods. Crystal structure of all the complexes indicated a mono negative bidentate coordination of Thiocarboxamide ligands to the palladium center via pyridine nitrogen and thiol sulfur and reveals a square planar geometry. The interaction of palladium(II) Thiocarboxamide complexes with calf thymus DNA (CT-DNA) studied by absorption and emission spectroscopic methods revealed that complexes 5-8 could interact with CT-DNA through intercalation. Further, the interaction of the palladium complexes with bovine serum albumin (BSA) was investigated using UV-Vis, fluorescence and synchronous fluorescence methods. The tryptophan and tyrosine residues in BSA as model protein was quenched by the complexes in a static quenching process. The radical scavenging ability of all the complexes was accessed by in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical and ABTS radicals and was found to be excellent. Further, the anti-cancer activity of complexes 5-8 against HeLa, MCF-7 and NIH-3T3 cell line has been studied. Though the complexes 5, 6 and 8 showed more potent anticancer activity than cisplatin, complex 5 was found to be superior. (C) 2014 Elsevier B.V. All rights reserved.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium(II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)2(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO(AsPh3)3] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV–vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde
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DNA/protein interaction and cytotoxicity of palladium(II) complexes of Thiocarboxamide ligands
Inorganica Chimica Acta, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Nallasamy Dharmaraj, Yu LiuAbstract:Four planar palladium(II) complexes with general formula [Pd(Cl)(L)(PPh3)] (HL = N-substituted pyridine-2- Thiocarboxamide) have been synthesized and characterized by analytical, spectral (IR, UV-Vis and H-1, C-13 and P-31 NMR) and single crystal X-ray methods. Crystal structure of all the complexes indicated a mono negative bidentate coordination of Thiocarboxamide ligands to the palladium center via pyridine nitrogen and thiol sulfur and reveals a square planar geometry. The interaction of palladium(II) Thiocarboxamide complexes with calf thymus DNA (CT-DNA) studied by absorption and emission spectroscopic methods revealed that complexes 5-8 could interact with CT-DNA through intercalation. Further, the interaction of the palladium complexes with bovine serum albumin (BSA) was investigated using UV-Vis, fluorescence and synchronous fluorescence methods. The tryptophan and tyrosine residues in BSA as model protein was quenched by the complexes in a static quenching process. The radical scavenging ability of all the complexes was accessed by in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical and ABTS radicals and was found to be excellent. Further, the anti-cancer activity of complexes 5-8 against HeLa, MCF-7 and NIH-3T3 cell line has been studied. Though the complexes 5, 6 and 8 showed more potent anticancer activity than cisplatin, complex 5 was found to be superior. (C) 2014 Elsevier B.V. All rights reserved.
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Palladium(II) Thiocarboxamide complexes: synthesis, characterisation and application to catalytic Suzuki coupling reactions
Dalton transactions (Cambridge England : 2003), 2012Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Yu LiuAbstract:A simple route to synthesise palladium(II) complexes from the reaction of N-substituted pyridine-2-Thiocarboxamide ligands and PdCl2(PPh3)(2) has been developed. The new complexes are very soluble in common solvents and have been fully characterised (elemental analysis, FT-IR, H-1, P-31, C-13-NMR), including an X-ray diffraction analysis. The molecular structures of all the complexes were determined and reveal the presence of square planar geometry around Pd with little distortion. The complexes were tested in the Suzuki coupling of electronically deactivated aryl and heteroaryl bromides and were found to have much greater activity, without using any promoting additives or phase transfer agent under aerobic conditions. Higher reaction rates are obtained by varying R substituents on the aromatic ring of pyridine-2-Thiocarboxamide. The effect of other variables on the cross-coupling reaction, such as temperature, solvent and base, is also reported.
Elangovan Sindhuja - One of the best experts on this subject based on the ideXlab platform.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
Organometallics, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium (II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)(2)(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO-(AsPh3)(3)] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde.
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dna protein interaction and cytotoxicity of palladium ii complexes of Thiocarboxamide ligands
Inorganica Chimica Acta, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Nallasamy Dharmaraj, Yu LiuAbstract:Four planar palladium(II) complexes with general formula [Pd(Cl)(L)(PPh3)] (HL = N-substituted pyridine-2- Thiocarboxamide) have been synthesized and characterized by analytical, spectral (IR, UV-Vis and H-1, C-13 and P-31 NMR) and single crystal X-ray methods. Crystal structure of all the complexes indicated a mono negative bidentate coordination of Thiocarboxamide ligands to the palladium center via pyridine nitrogen and thiol sulfur and reveals a square planar geometry. The interaction of palladium(II) Thiocarboxamide complexes with calf thymus DNA (CT-DNA) studied by absorption and emission spectroscopic methods revealed that complexes 5-8 could interact with CT-DNA through intercalation. Further, the interaction of the palladium complexes with bovine serum albumin (BSA) was investigated using UV-Vis, fluorescence and synchronous fluorescence methods. The tryptophan and tyrosine residues in BSA as model protein was quenched by the complexes in a static quenching process. The radical scavenging ability of all the complexes was accessed by in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical and ABTS radicals and was found to be excellent. Further, the anti-cancer activity of complexes 5-8 against HeLa, MCF-7 and NIH-3T3 cell line has been studied. Though the complexes 5, 6 and 8 showed more potent anticancer activity than cisplatin, complex 5 was found to be superior. (C) 2014 Elsevier B.V. All rights reserved.
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Direct Synthesis of Amides from Coupling of Alcohols and Amines Catalyzed by Ruthenium(II) Thiocarboxamide Complexes under Aerobic Conditions
2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Sundarraman Balaji, Yu LiuAbstract:Four octahedral ruthenium(II) Thiocarboxamide complexes of the general formula [RuClCO(AsPh3)2(L)] (L = N-substituted pyridine-2-Thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO(AsPh3)3] with 1 equiv of Thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV–vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of Thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) Thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde
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DNA/protein interaction and cytotoxicity of palladium(II) complexes of Thiocarboxamide ligands
Inorganica Chimica Acta, 2014Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Nallasamy Dharmaraj, Yu LiuAbstract:Four planar palladium(II) complexes with general formula [Pd(Cl)(L)(PPh3)] (HL = N-substituted pyridine-2- Thiocarboxamide) have been synthesized and characterized by analytical, spectral (IR, UV-Vis and H-1, C-13 and P-31 NMR) and single crystal X-ray methods. Crystal structure of all the complexes indicated a mono negative bidentate coordination of Thiocarboxamide ligands to the palladium center via pyridine nitrogen and thiol sulfur and reveals a square planar geometry. The interaction of palladium(II) Thiocarboxamide complexes with calf thymus DNA (CT-DNA) studied by absorption and emission spectroscopic methods revealed that complexes 5-8 could interact with CT-DNA through intercalation. Further, the interaction of the palladium complexes with bovine serum albumin (BSA) was investigated using UV-Vis, fluorescence and synchronous fluorescence methods. The tryptophan and tyrosine residues in BSA as model protein was quenched by the complexes in a static quenching process. The radical scavenging ability of all the complexes was accessed by in vitro antioxidant assays involving DPPH radical, hydroxyl radical, nitric oxide radical and ABTS radicals and was found to be excellent. Further, the anti-cancer activity of complexes 5-8 against HeLa, MCF-7 and NIH-3T3 cell line has been studied. Though the complexes 5, 6 and 8 showed more potent anticancer activity than cisplatin, complex 5 was found to be superior. (C) 2014 Elsevier B.V. All rights reserved.
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Palladium(II) Thiocarboxamide complexes: synthesis, characterisation and application to catalytic Suzuki coupling reactions
Dalton transactions (Cambridge England : 2003), 2012Co-Authors: Elangovan Sindhuja, Rengan Ramesh, Yu LiuAbstract:A simple route to synthesise palladium(II) complexes from the reaction of N-substituted pyridine-2-Thiocarboxamide ligands and PdCl2(PPh3)(2) has been developed. The new complexes are very soluble in common solvents and have been fully characterised (elemental analysis, FT-IR, H-1, P-31, C-13-NMR), including an X-ray diffraction analysis. The molecular structures of all the complexes were determined and reveal the presence of square planar geometry around Pd with little distortion. The complexes were tested in the Suzuki coupling of electronically deactivated aryl and heteroaryl bromides and were found to have much greater activity, without using any promoting additives or phase transfer agent under aerobic conditions. Higher reaction rates are obtained by varying R substituents on the aromatic ring of pyridine-2-Thiocarboxamide. The effect of other variables on the cross-coupling reaction, such as temperature, solvent and base, is also reported.
Ramasamy Raj Kumar - One of the best experts on this subject based on the ideXlab platform.
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synthesis and structure of nickel ii Thiocarboxamide complexes effect of ligand substitutions on dna protein binding antioxidant and cytotoxicity
RSC Advances, 2015Co-Authors: Ramasamy Raj Kumar, Mohamed Kasim Mohamed Subarkhan, Rengan RameshAbstract:Four low spin d8 nickel(II) square planar complexes with general formula [Ni(L)2] (where L = monobasic N, S bidentate Thiocarboxamides) have been synthesized from the reaction of Ni(OAc)2·4H2O with 2 equivalent of Thiocarboxamide ligands in ethanol. The complexes have been fully characterized by analytical, spectral (FT-IR, UV-Vis, 1H and 13C NMR) and single crystal X-ray methods. Molecular structure of one of the complexes indicates a mono anionic bidendate coordination of Thiocarboxamide ligands to the nickel via pyridine nitrogen and thiolate sulphur and reveal a square planar geometry. The binding interaction of nickel(II) Thiocarboxamide complexes with calf-thymus DNA (CT-DNA) was studied by electronic and emission spectroscopic methods revealed that complexes 1–4 could interact with CT-DNA via intercalation mode. DNA cleavage experiment shows that all the complexes cleave pUC19 supercoiled DNA in the presence of an activator like H2O2. The CD spectral study shows that binding of the complexes to DNA does not lead to any significant changes in the conformation of CT-DNA. Further, the protein binding ability of the nickel(II) Thiocarboxamide complexes with the BSA was investigated by UV-Vis, fluorescence and synchronous fluorescence methods and a static quenching mechanism was observed for their interaction with BSA. The free radical scavenging ability of all the complexes was evaluated by in vitro antioxidant assays involving DPPH radical, hydroxyl radical and nitric oxide radical and was found to be excellent. Moreover, the efficiency of complexes 1–4 to arrest the growth of HeLa and MG-63 cell lines has been studied along with the cell viability test against the non-cancerous cells NIH-3T3 under in vitro condition. Complex 3 was found to be the highest anticancer activity among the nickel complexes.
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Synthesis and structure of nickel(ii) Thiocarboxamide complexes: effect of ligand substitutions on DNA/protein binding, antioxidant and cytotoxicity
RSC Advances, 2015Co-Authors: Ramasamy Raj Kumar, Mohamed Kasim Mohamed Subarkhan, Rengan RameshAbstract:Four low spin d8 nickel(II) square planar complexes with general formula [Ni(L)2] (where L = monobasic N, S bidentate Thiocarboxamides) have been synthesized from the reaction of Ni(OAc)2·4H2O with 2 equivalent of Thiocarboxamide ligands in ethanol. The complexes have been fully characterized by analytical, spectral (FT-IR, UV-Vis, 1H and 13C NMR) and single crystal X-ray methods. Molecular structure of one of the complexes indicates a mono anionic bidendate coordination of Thiocarboxamide ligands to the nickel via pyridine nitrogen and thiolate sulphur and reveal a square planar geometry. The binding interaction of nickel(II) Thiocarboxamide complexes with calf-thymus DNA (CT-DNA) was studied by electronic and emission spectroscopic methods revealed that complexes 1–4 could interact with CT-DNA via intercalation mode. DNA cleavage experiment shows that all the complexes cleave pUC19 supercoiled DNA in the presence of an activator like H2O2. The CD spectral study shows that binding of the complexes to DNA does not lead to any significant changes in the conformation of CT-DNA. Further, the protein binding ability of the nickel(II) Thiocarboxamide complexes with the BSA was investigated by UV-Vis, fluorescence and synchronous fluorescence methods and a static quenching mechanism was observed for their interaction with BSA. The free radical scavenging ability of all the complexes was evaluated by in vitro antioxidant assays involving DPPH radical, hydroxyl radical and nitric oxide radical and was found to be excellent. Moreover, the efficiency of complexes 1–4 to arrest the growth of HeLa and MG-63 cell lines has been studied along with the cell viability test against the non-cancerous cells NIH-3T3 under in vitro condition. Complex 3 was found to be the highest anticancer activity among the nickel complexes.