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Synthesis and Characterisation of Copper(II) Complexes with Tridentate NNO Functionalized Ligand: Density Function Theory Study, DNA Binding Mechanism, Optical Properties, and Biological Application.

Hazra M, Dolai T, Pandey A, Dey SK, Patra A - Bioinorg Chem Appl (2014)

Bottom Line: All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding.The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices.Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation.

View Article: PubMed Central - PubMed

Affiliation: Postgraduate Department of Chemistry, Midnapore College, Midnapore 721101, India ; Department of Chemistry, Sidho-Kanho-Birsha University, Purulia, West Bengal 723101, India.

ABSTRACT
The photo physical properties of two mononuclear pentacoordinated copper(II) complexes formulated as [Cu(L)(Cl)(H2O)] (1) and [Cu(L)(Br)(H2O)] (2) HL = (1-[(3-methyl-pyridine-2-ylimino)-methyl]-naphthalen-2-ol) were synthesized and characterized by elemental, physicochemical, and spectroscopic methods. The density function theory calculations are used to investigate the electronic structures and the electronic properties of ligand and complex. The interactions of copper(II) complexes towards calf thymus DNA were examined with the help of absorption, viscosity, and fluorescence spectroscopic techniques at pH 7.40. All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding. The optical absorption and fluorescence emission properties of microwires were characterized by fluorescence microscope. From a spectroscopic viewpoint, all compounds strongly emit green light in the solid state. The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices. Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation. Moreover, the antioxidant study of the ligand and complexes is evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assays, which demonstrate that the complexes are of higher antioxidant activity than free ligand.

No MeSH data available.


Emission spectra (a, b) of the CT-DNA-EB system in Tris-HCl buffer upon the titration of the copper(II) complex-1 (a) and complex-2 (b). λex = 522 nm; [EB] = 9.2 × 10−6 mol L−1, [DNA] = 1.22 × 10−6; [complex]: a 0.0, b 1.36 × 10−5, c 2.72 × 10−5, d 4.08 × 10−5, e 5.44 × 10−5,  f 6.80 × 10−5, g 8.16 × 10−5, h 9.52 × 10−5 mol L−1. Arrow shows the intensity change upon the increase of the complex concentration. Plot of Io/I against [complex] in fluorescence quenching of CT-DNA-EB system in Tris-HCL buffer (c, d), complex-1 (c), and complex-2 (d), respectively.
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fig4: Emission spectra (a, b) of the CT-DNA-EB system in Tris-HCl buffer upon the titration of the copper(II) complex-1 (a) and complex-2 (b). λex = 522 nm; [EB] = 9.2 × 10−6 mol L−1, [DNA] = 1.22 × 10−6; [complex]: a 0.0, b 1.36 × 10−5, c 2.72 × 10−5, d 4.08 × 10−5, e 5.44 × 10−5,  f 6.80 × 10−5, g 8.16 × 10−5, h 9.52 × 10−5 mol L−1. Arrow shows the intensity change upon the increase of the complex concentration. Plot of Io/I against [complex] in fluorescence quenching of CT-DNA-EB system in Tris-HCL buffer (c, d), complex-1 (c), and complex-2 (d), respectively.

Mentions: Fluorescence quenching is a helpful method to study the reactivity of chemical and biological systems since it allows nonintrusive dimensions of substances in low concentration under physiological circumstances [41], useful information about binding mechanisms and providing clues to the nature of binding. Fluorescence intensity of a compound can be quenched as a result of molecular interactions, such as excited state reactions, molecular rearrangements, ground state complex formation, and collisional quenching. Fluorescence intensity of EB bound to CT-DNA shows a decreasing trend with the increasing concentration of the complexes as shown in Figure 4. The quenching of EB bound to DNA by the complexesis in agreement with the linear Stern-Volmer equation [42]:(2)I0I=1+Ksv[Q],where I0 and I represent the fluorescence intensities in the absence and presence of quencher, respectively. Ksv is a linear Stern-Volmer quenching constant and Q is the concentration of quencher. The Ksv value calculated from the plot is shown in Figure 4 of I0/I versus [complex]. The value of Stern-Volmer quenching constant (Ksv) was 1.94 × 104 (R = 0.98576 up to four points) and 1.34 × 104 (R = 0.98818 up to four points) for complex-1 and complex-2, respectively. The Ksv value in fluorescence spectral studies indicates the nonintercalative binding interaction with DNA and probable groove binding or external binding is suggested for complex-1 and complex-2, which is supported by viscosity measurements. Thus the binding interaction is groove binding mode but not involved in intercalative binding. All the Stern-Volmer plots represent a good linear relationship indicating a strong affinity of the copper(II) complexes to CT-DNA.


Synthesis and Characterisation of Copper(II) Complexes with Tridentate NNO Functionalized Ligand: Density Function Theory Study, DNA Binding Mechanism, Optical Properties, and Biological Application.

Hazra M, Dolai T, Pandey A, Dey SK, Patra A - Bioinorg Chem Appl (2014)

Emission spectra (a, b) of the CT-DNA-EB system in Tris-HCl buffer upon the titration of the copper(II) complex-1 (a) and complex-2 (b). λex = 522 nm; [EB] = 9.2 × 10−6 mol L−1, [DNA] = 1.22 × 10−6; [complex]: a 0.0, b 1.36 × 10−5, c 2.72 × 10−5, d 4.08 × 10−5, e 5.44 × 10−5,  f 6.80 × 10−5, g 8.16 × 10−5, h 9.52 × 10−5 mol L−1. Arrow shows the intensity change upon the increase of the complex concentration. Plot of Io/I against [complex] in fluorescence quenching of CT-DNA-EB system in Tris-HCL buffer (c, d), complex-1 (c), and complex-2 (d), respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig4: Emission spectra (a, b) of the CT-DNA-EB system in Tris-HCl buffer upon the titration of the copper(II) complex-1 (a) and complex-2 (b). λex = 522 nm; [EB] = 9.2 × 10−6 mol L−1, [DNA] = 1.22 × 10−6; [complex]: a 0.0, b 1.36 × 10−5, c 2.72 × 10−5, d 4.08 × 10−5, e 5.44 × 10−5,  f 6.80 × 10−5, g 8.16 × 10−5, h 9.52 × 10−5 mol L−1. Arrow shows the intensity change upon the increase of the complex concentration. Plot of Io/I against [complex] in fluorescence quenching of CT-DNA-EB system in Tris-HCL buffer (c, d), complex-1 (c), and complex-2 (d), respectively.
Mentions: Fluorescence quenching is a helpful method to study the reactivity of chemical and biological systems since it allows nonintrusive dimensions of substances in low concentration under physiological circumstances [41], useful information about binding mechanisms and providing clues to the nature of binding. Fluorescence intensity of a compound can be quenched as a result of molecular interactions, such as excited state reactions, molecular rearrangements, ground state complex formation, and collisional quenching. Fluorescence intensity of EB bound to CT-DNA shows a decreasing trend with the increasing concentration of the complexes as shown in Figure 4. The quenching of EB bound to DNA by the complexesis in agreement with the linear Stern-Volmer equation [42]:(2)I0I=1+Ksv[Q],where I0 and I represent the fluorescence intensities in the absence and presence of quencher, respectively. Ksv is a linear Stern-Volmer quenching constant and Q is the concentration of quencher. The Ksv value calculated from the plot is shown in Figure 4 of I0/I versus [complex]. The value of Stern-Volmer quenching constant (Ksv) was 1.94 × 104 (R = 0.98576 up to four points) and 1.34 × 104 (R = 0.98818 up to four points) for complex-1 and complex-2, respectively. The Ksv value in fluorescence spectral studies indicates the nonintercalative binding interaction with DNA and probable groove binding or external binding is suggested for complex-1 and complex-2, which is supported by viscosity measurements. Thus the binding interaction is groove binding mode but not involved in intercalative binding. All the Stern-Volmer plots represent a good linear relationship indicating a strong affinity of the copper(II) complexes to CT-DNA.

Bottom Line: All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding.The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices.Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation.

View Article: PubMed Central - PubMed

Affiliation: Postgraduate Department of Chemistry, Midnapore College, Midnapore 721101, India ; Department of Chemistry, Sidho-Kanho-Birsha University, Purulia, West Bengal 723101, India.

ABSTRACT
The photo physical properties of two mononuclear pentacoordinated copper(II) complexes formulated as [Cu(L)(Cl)(H2O)] (1) and [Cu(L)(Br)(H2O)] (2) HL = (1-[(3-methyl-pyridine-2-ylimino)-methyl]-naphthalen-2-ol) were synthesized and characterized by elemental, physicochemical, and spectroscopic methods. The density function theory calculations are used to investigate the electronic structures and the electronic properties of ligand and complex. The interactions of copper(II) complexes towards calf thymus DNA were examined with the help of absorption, viscosity, and fluorescence spectroscopic techniques at pH 7.40. All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding. The optical absorption and fluorescence emission properties of microwires were characterized by fluorescence microscope. From a spectroscopic viewpoint, all compounds strongly emit green light in the solid state. The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices. Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation. Moreover, the antioxidant study of the ligand and complexes is evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assays, which demonstrate that the complexes are of higher antioxidant activity than free ligand.

No MeSH data available.