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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.


Electronic spectral titration (a, b) of complex-1 (a) and complex-2 (b) with CT-DNA at 266 nm in Tris-HCl buffer; [complex] = 2.34 × 10−5; [DNA]: a 0.0, b 1.22 × 10−6, c 2.44 × 10−6, d 3.66 × 10−6, e 4.88 × 10−6, f 6.10 × 10−6 mol L−1. The arrow denotes the gradual increase of DNA concentration. Plot of [DNA]/(εa − εf) versus [DNA] for the absorption titration of CT-DNA with the copper(II) complex-1 (c) and complex-2 (d) in Tris-HCl buffer at the (c, d).
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fig3: Electronic spectral titration (a, b) of complex-1 (a) and complex-2 (b) with CT-DNA at 266 nm in Tris-HCl buffer; [complex] = 2.34 × 10−5; [DNA]: a 0.0, b 1.22 × 10−6, c 2.44 × 10−6, d 3.66 × 10−6, e 4.88 × 10−6, f 6.10 × 10−6 mol L−1. The arrow denotes the gradual increase of DNA concentration. Plot of [DNA]/(εa − εf) versus [DNA] for the absorption titration of CT-DNA with the copper(II) complex-1 (c) and complex-2 (d) in Tris-HCl buffer at the (c, d).

Mentions: In general, the hyperchromism and hypochromism were regarded as spectral features for DNA double-helix structural change when DNA reacted with other molecules. The hyperchromism originates from the breakage of the DNA duplex secondary structure; the hypochromism originates from the stabilization of the DNA duplex by either the intercalation binding mode or the electrostatic effect of small molecules. It is reported that if the aromatic ring of the molecule closely matches with the helical turn of the CT-DNA groove, the aromatic rings of the ligand interact with DNA in Tris-HCl buffer through the formation of the van der Waals contacts or hydrogen bonds in the DNA grooves. The binding of the copper(II) complex to the CT-DNA helix is examined by an increase of the absorption band (c.a. 264 nm) of copper(II) complex. This increasing absorbance indicates that there is the involvement of strong interactions between complex and the base pairs of DNA [37]. The absorption spectra of the copper(II) complexes in the absence and presence of CT-DNA are shown in Figure 3. A hyperchromism was also observed for a copper(II) complex with a ligand bearing -OH group. The extent of the hyperchromism in the charge transfer band is generally consistent with the strength of interaction [38]. As DNA double helix possesses many hydrogen bonding sites which are accessible both in the minor and in the major grooves, it is likely that the –OH group of the ternary complex forms hydrogen bonds with DNA, which may contribute to the hyperchromism observed in absorption spectra. The increasing absorbance indicates there is groove binding modes.


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)

Electronic spectral titration (a, b) of complex-1 (a) and complex-2 (b) with CT-DNA at 266 nm in Tris-HCl buffer; [complex] = 2.34 × 10−5; [DNA]: a 0.0, b 1.22 × 10−6, c 2.44 × 10−6, d 3.66 × 10−6, e 4.88 × 10−6, f 6.10 × 10−6 mol L−1. The arrow denotes the gradual increase of DNA concentration. Plot of [DNA]/(εa − εf) versus [DNA] for the absorption titration of CT-DNA with the copper(II) complex-1 (c) and complex-2 (d) in Tris-HCl buffer at the (c, d).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4214117&req=5

fig3: Electronic spectral titration (a, b) of complex-1 (a) and complex-2 (b) with CT-DNA at 266 nm in Tris-HCl buffer; [complex] = 2.34 × 10−5; [DNA]: a 0.0, b 1.22 × 10−6, c 2.44 × 10−6, d 3.66 × 10−6, e 4.88 × 10−6, f 6.10 × 10−6 mol L−1. The arrow denotes the gradual increase of DNA concentration. Plot of [DNA]/(εa − εf) versus [DNA] for the absorption titration of CT-DNA with the copper(II) complex-1 (c) and complex-2 (d) in Tris-HCl buffer at the (c, d).
Mentions: In general, the hyperchromism and hypochromism were regarded as spectral features for DNA double-helix structural change when DNA reacted with other molecules. The hyperchromism originates from the breakage of the DNA duplex secondary structure; the hypochromism originates from the stabilization of the DNA duplex by either the intercalation binding mode or the electrostatic effect of small molecules. It is reported that if the aromatic ring of the molecule closely matches with the helical turn of the CT-DNA groove, the aromatic rings of the ligand interact with DNA in Tris-HCl buffer through the formation of the van der Waals contacts or hydrogen bonds in the DNA grooves. The binding of the copper(II) complex to the CT-DNA helix is examined by an increase of the absorption band (c.a. 264 nm) of copper(II) complex. This increasing absorbance indicates that there is the involvement of strong interactions between complex and the base pairs of DNA [37]. The absorption spectra of the copper(II) complexes in the absence and presence of CT-DNA are shown in Figure 3. A hyperchromism was also observed for a copper(II) complex with a ligand bearing -OH group. The extent of the hyperchromism in the charge transfer band is generally consistent with the strength of interaction [38]. As DNA double helix possesses many hydrogen bonding sites which are accessible both in the minor and in the major grooves, it is likely that the –OH group of the ternary complex forms hydrogen bonds with DNA, which may contribute to the hyperchromism observed in absorption spectra. The increasing absorbance indicates there is groove binding modes.

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.