Herring Sperm DNA Research Articles

Well-Optimized Conjugated GO-DNA Nanosystem for Sensitive Ratiometric pH Detection in Live Cells.

Intracellular pH is a vital parameter which can reflect the physiological process, and the detection of intracellular pH with a high signal-to-noise ratio (SNR) remains a challenge. Compared to pH biosensors based on a single-wavelength signal, it is much easier to obtain better sensitivity and higher SNR from the biosensors by two-wavelength ratiometric signals. In this study, we used DNA-grafted graphene oxide (GO) to ratiometrically detect intracellular pH ranging from basic to acidic. A high SNR with a 35-fold difference in the ratiometric output has been achieved through careful optimization: (1) A high DNA conjugation yield of 45% has been gained through utilizing the partial double-stranded assembly strategy. (2) Herring sperm DNA (HSD) plays an important role in improving the sensitivity of the nanosystem by purifying and passivating the surface of GO; therefore, the concentration of HSD has been optimized to pursue the most sensitive ratiometric response. Apart from the ultrahigh SNR, fabricated GO-AR-Cy5/IFO-Cy3 exhibited excellent stability and biocompatibility in biological environments. Further experiments demonstrated that the nanosystem worked well in live cells in response to pH changes. It is possible to distinguish small pH differences and realize quantitative detection based on ratiometric fluorescence imaging by laser scanning confocal microscope analysis, which makes the nanosystem a promising candidate for further biological study and clinical applications.

Synthesis and crystal structure of bicopper(II) complexes: The influence of bridging ligands on DNA/BSA binding behaviors and in vitro antitumor activity

Two new μ-oxamide or μ-oxamate bridged bicopper(II) complexes, [Cu2(mapox)(bpy)2](ClO4)2 (1) and Cu2(mapoa)(CH3OH)(bpy)2(pic)2·0.5H2O (2) (H2mapox = N,N′-bis[3-(methylamino)propyl]-oxamide, H2mapoa = N-[3-(methylamino)propyl]oxamate, bpy = 2,2′-bipyridine, pic = picrate anions), have been synthesized and characterized by elemental analyses, molar conductance measurement, spectroscopic studies and single-crystal X-ray diffraction. In complex 1, both the copper(II) atoms acquire a square-pyramidal coordination geometry. The distance between Cu1 and Cu2 atoms is 5.2541(8) Å. The structure of complex 2 contains two bicopper(II) cations [Cu2(mapoa)(CH3OH)(bpy)2]2+, in which the Cu atoms acquire distorted square-pyramid coordination geometry (Cu1, Cu2, Cu4) or distorted trigonal bipyramid coordination geometry (Cu3). The Cu⋯Cu separations are 5.2316(8) Å (Cu1, Cu2) and 5.2187(7) Å (Cu3, Cu4), respectively. The interaction between complexes 1 and 2 and herring Sperm DNA (HS-DNA) were studied by using UV absorption and fluorescence spectra, electrochemical techniques and viscometry. The results indicated that both of the two complexes could bind to HS-DNA by intercalation with the order 1 > 2. Protein binding properties investigations reveal that the two complexes could bind to bovine serum albumin (BSA) by the static quenching mechanism. The in vitro cytotoxicities experiments reveal that complex 1 exhibit better growth-inhibitory effects than complex 2 on human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549.

Bipyrazole-based palladium(II) complexes as DNA intercalator and artificial metallonuclease

Substituted 3′-methyl-1′,2-diphenyl-3,4-dihydro-1′H,2H-3,4′-bipyrazole and their square planar palladium(II) complexes of type [Pd(4n)Cl2], where 4n = bipyrazole-based ligands, have been synthesized. The compounds have been characterized by various techniques like elemental analysis, mass, absorption, IR, 1H NMR and 13C NMR spectroscopy. The complexes have been further analyzed by thermogravimetric analysis (TGA), conductance measurement and energy-dispersive X-ray spectroscopy (EDX). Interaction between compounds and herring sperm DNA has been studied by absorption titration, viscosity measurement, ethidium bromide displacement titration, and molecular docking study. The binding strength between compounds and DNA has been checked in terms of Kb, Ksv, and Kf values; while spontaneity of interaction has been checked by evaluating thermodynamic parameters like Gibb’s free energy, enthalpy change (∆H°) and entropy change (∆S°). The plasmid cleavage efficacy of complexes has been evaluated by gel electrophoresis technique. The minimum inhibitory concentration of compounds has been evaluated against pathogens such as Staphylococcus aureus, Escherichia coli, B. subtilis, S. marcescens and Pseudomonas aeruginosa. The in vivo and in vitro cytotoxic activity has been performed using cell viability assay and brine shrimp lethality bioassay.

Bioactive mono/bis (carboxyamide) based Co (II), Ni (II) and Cu (II) complexes: Synthesis, Characterization, DNA binding and Anticancer Potentials

Bioactive carboxyamide ligated CuII (1), CoII (2) and NiII (3) complexes have been synthesized and characterized using various physico‐chemical techniques. In particular, the occurred slightly distorted square planar geometry in complex 1 was confirmed by single X‐ray crystal structure. Their (1, 2 and 3) potential interactions with herring sperm DNA (HS‐DNA) have been investigated using spectral and electrochemical techniques. All these studies suggested that the complex 1 could partially penetrated in the sugar phosphate backbone and stacked in between the DNA base pairs, while the other complexes 2 & 3 could bound only on the grooves of HS‐DNA due to their bi‐ligated architecture around the metal centre. The potent cytotoxicity of L and its complexes 1–3 was also evaluated against AGS human gastric cancer cells. Hoechst 33342/PI double staining images revealed that the complexes significantly induced cell death through apoptosis. In vivo administration of complex 1 remarkably inhibits the tumor growth in male Swiss albino mice, moreover it did not show any hepatotoxicity in mice. All these observed results suggested that these complexes may utilized as good conventional therapeutic agents in the near feature after a series of biological assessments.

Using two-fluid nozzle for spray freeze drying to produce porous powder formulation of naked siRNA for inhalation

Spray freeze drying is an attractive technology to produce powder formulation for inhalation. It can be used to generate large porous particles which tend to aerosolize efficiently and do not aggregate readily. It also avoids material to be exposed to elevated temperature. In this study, we reported the use of two-fluid nozzle to produce spray freeze dried powder of small interfering RNA (siRNA). The effect of atomization gas flow rate and liquid feed rate were inspected initially using herring sperm DNA (hsDNA) as nucleic acid model. The atomization gas flow rate was found to have a major impact on the aerosol properties. The higher the atomization gas flow rate, the smaller the particle size, the higher the fine particle fraction (FPF). In contrast, the liquid feed rate had very minor effect. Subsequently, spray freeze dried siRNA powder was produced at various atomization gas flow rates. The particles produced were highly porous as examined with the scanning electron microscopy, and the structural integrity of the siRNA was demonstrated with gel electrophoresis. The gene-silencing effect of the siRNA was also successfully preserved in vitro. The best performing siRNA formulation was prepared at the highest atomization gas flow rate investigated with a moderate FPF of 30%. However, this was significantly lower than that obtained with the corresponding hsDNA counterparts (FPF ∼57%). A direct comparison between the hsDNA and siRNA formulations revealed that the former exhibited a lower density, hence a smaller aerodynamic diameter despite similar geometric size.

A Spectroscopic Study of the Interaction Between the Bismarck Brown R–Eu(III) Complex and DNA

The interaction of the Eu(III)–BBR complex with herring sperm DNA is investigated using an acridine orange (AO) probe for UV-vis absorption spectroscopy and fluorescence spectroscopy. The results indicate that both the AO probe and the Eu(III)–BBR complex can intercalate into the base pairs of DNA. The binding constants of the Eu(III)–BBR complex with DNA are $$ {K}_{298.15K}^{\theta } $$ = 1.58·104 L/mol and $$ {K}_{308.15K}^{\theta } $$ = 9.35·104 L/mol, and the binding process is entropydriven. It is shown that the interaction modes between the Eu(III)–BBR complex and DNA include groove binding and intercalative binding. The mechanism of the interaction between the Eu(III)–BBR complex and DNA will provide an important theoretical basis for the synthesis of new drugs.

Modulation of probe-genomic DNA interaction within the confined interior of a reverse micelle: Is the bulk-like properties of water truly achieved in large reverse micelles?

The prime motivation of the present study is to explore the effect of reverse micellar confinement on the binding interaction of an anthracene-based probe 9-methyl anthroate with herring-sperm DNA. The structural modification of the genomic DNA from its native B-form to the non-native C-form and subsequently to the condensed Ψ-form as a function of the level of hydration (W0, defined as [water] / [surfactant]) of the reverse micellar core is found to reveal a remarkable regulatory role on the stability of the stacking interaction (intercalation) of the probe within the DNA helix; the interaction being progressively stabilized at higher W0. Particularly, a close perusal of the dynamical aspects of the interaction is found to be counter-intuitive to the popular notion of the properties of the confined water within the reverse micelles typically approaching bulk-like properties at sufficiently high hydration levels (W0 > 10).

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

4-Aminopyridine based amide derivatives as dual inhibitors of tissue non-specific alkaline phosphatase and ecto-5′-nucleotidase with potential anticancer activity

Ecto-nucleotidase members i.e., ecto-5′-nucleotidase and alkaline phosphatase, hydrolyze extracellular nucleotides and play an important role in purinergic signaling. Their overexpression are implicated in a variety of pathological states, including immunological diseases, bone mineralization, vascular calcification and cancer, and thus they represent an emerging drug targets. In order to design potent and selective inhibitors, new derivatives of 4-aminopyridine have been synthesized (10a-10m) and their structures were established on the basis of spectral data. The effect of nature and position of substituent was interestingly observed and justified on the basis of their detailed structure activity relationships (SARs) against both families of ecto-nucleotidase. Compound 10a displayed significant inhibition (IC50 ± SEM = 0.25 ± 0.05 µM) that was found ≈168 fold more potent as compared to previously reported inhibitor suramin (IC50 ± SEM = 42.1 ± 7.8 µM). This compound exhibited 6 times more selectivity towards h-TNAP over h-e5′NT. The anticancer potential and mechanism were also established using cell viability assay, flow cytometric analysis and nuclear staining. Molecular docking studies were also carried out to gain insight into the binding interaction of potent compounds within the respective enzyme pockets and herring-sperm DNA.

Synthesis, characterization and biological applications of substituted pyrazolone core based platinum(II) organometallic compounds

New series of organometallic platinum(II) compounds (I-VI) containing the 2-phenyl-5-methyl pyrazole-3-one derivatives ligands (L1-L6) were synthesized and characterized by spectroscopic and physicochemical techniques. The synthesized compounds were screen for their in vitro antibacterial activity against two Gram(+ve) and three Gram(−ve) bacterial species. In vitro cytotoxicity against brine shrimp lethality bioassay and in vitro cellular level cytotoxicity against S. pombe cells were carried out for the synthesized compounds. Complexes (I-VI) exhibit excellent cytotoxicity as compared to ligands (L1-L6). DNA interaction and DNA cleavage study of the synthesized ligands and complexes were carried out using absorption titration spectroscopy, fluorescence quenching analysis, viscosity measurements, molecular docking study and agarose gel electrophoresis. The interactions of compounds towards herring sperm DNA (HS-DNA) was examined. The binding constant (Kb), Stern-Volmer quenching constant (Ksv) and associative binding constant (Ka) of the synthesized ligands and complexes were observed in the range of 0.138–5.580 × 105 M−1, 1.1 × 102 to 7.0 × 103 M−1 and 1.871 × 103 to 1.711 × 105 M−1, respectively. In molecular docking study, binding energy of compounds were observed in the range of −240.74 to −325.79 kJmol-1. The results propose that all the compounds could interact with HS-DNA via the partial intercalative mode of binding.

Spray freeze drying of small nucleic acids as inhaled powder for pulmonary delivery

The therapeutic potential of small nucleic acids such as small interfering RNA (siRNA) to treat lung diseases has been successfully demonstrated in many in vivo studies. A major barrier to their clinical application is the lack of a safe and efficient inhaled formulation. In this study, spray freeze drying was employed to prepare dry powder of small nucleic acids. Mannitol and herring sperm DNA were used as bulking agent and model of small nucleic acid therapeutics, respectively. Formulations containing different solute concentration and DNA concentration were produced. The scanning electron microscope (SEM) images showed that the porosity of the particles increased as the solute concentration decreased. Powders prepared with solute concentration of 5% w/v were found to maintain a balance between porosity and robustness. Increasing concentration of DNA improved the aerosol performance of the formulation. The dry powder formulation containing 2% w/w DNA had a median diameter of 12.5 µm, and the aerosol performance study using next generation impactor (NGI) showed an emitted fraction (EF) and fine particle fraction (FPF) of 91% and 28% respectively. This formulation (5% w/v solute concentration and 2% w/w nucleic acid) was adopted subsequently to produce siRNA powder. The gel retardation and liquid chromatography assays showed that the siRNA remained intact after spray freeze drying even in the absence of delivery vector. The siRNA powder formulation exhibited a high EF of 92.4% and a modest FPF of around 20%. Further exploration of this technology to optimise inhaled siRNA powder formulation is warranted.

Synthesis, structure, DNA/BSA binding and antibacterial studies of NNO tridentate Schiff base metal complexes

A new salicylaldehyde derived 2,4-diiodo-6-((2-phenylaminoethylimino)methyl)phenol Schiff base(L) and its transition metal complexes of the type MLCl where, M = Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been synthesized. The coordination mode of Schiff base holding NNO donor atoms with metal ions was well investigated by elemental analysis, ESI-mass as well as IR, UV–vis, CV and NMR spectral studies. The binding efficiency and mode of these complexes with biological macromolecules viz., herring sperm DNA (HS- DNA) and bovine serum albumin (BSA) have been explored through various spectroscopic techniques. The characteristic changes in absorption, emission and, circular dichroism spectra of the complexes with DNA indicate the noticeable interaction between them. From the all spectral information complexes could interact with DNA via non-intercalation mode of binding. The hyperchromisim in absorption band and hypochromisim in emission intensity of BSA with different complex concentrations shown significant information, and the binding affinity value has been predicted from Stern-Volmer plots. Further, all the complexes could cleave the circular plasmid pUC19 DNA efficiently by using an activator H2O2. The ligand and all metal(II) complexes showed good antibacterial activities. The molecular docking studies of the complexes with DNA were performed in order to make a comparison and conclusion with spectral technic results.

Effects of Near Infrared Radiation on DNA. DLS and ATR-FTIR Study

We presume that the primary effect of Near Infrared (NIR) radiation on aqueous solutions of biological molecules concerns modification of hydrogen bonded structures mainly the global and the hydration shell water molecules. Since water has a significant influence on the DNA structure, we expect that the thermal stability of DNA could be modified by NIR radiation. The herring sperm DNA was exposed to NIR radiation (700–1100nm) for 5, 10, and 20min periods. The temperature dependent infrared measurements were done for the thin films formed on the diamond ATR crystal from evaporated DNA solutions exposed and unexposed to NIR radiation. For the NIR-treated samples (at room temperature) the B form was better conserved than in the control sample independently of the irradiation period. Above 50°C a considerable increase in the A form was only observed for 10min NIR exposed samples. The hydrodynamic radius, (Rh), studied by the dynamic light scattering, showed drastic decrease with the increasing irradiation time. Principal components analysis (PCA) allowed to detect the spectral features correlated with the NIR effect and thermal stability of the DNA films. Obtained results strongly support the idea that the photoionization of water by NIR radiation in presence of DNA molecules is the main factor influencing on its physicochemical properties.

Synthesis, structure and in vitro antiproliferative activities of oxamido‐bridged dicopper(II) complexes: A comparative study of experimental evidence and molecular docking of DNA/protein binding

Two μ‐oxamido‐bridged dicopper(II) complexes, namely [Cu2(hmpoxd)(H2O)(phen)](ClO4) (1) and [Cu2(papo)(H2O)(phen)](ClO4)·2H2O (2), where H3hmpoxd and H3papo represent N‐(2‐hydroxy‐5‐methylphenyl)‐N′‐[3‐(dimethylamino)propyl]oxamide and N‐(2‐hydroxylphenyl)‐N′‐(3‐aminopropyl)oxamide, respectively, and phen represents 1,10‐phenanthroline, were synthesized. Single‐crystal X‐ray crystallography and other methods revealed that the two copper(II) ions in complex 1 are bridged by the cis‐hmpoxd3− with Cu···Cu separation of 5.1896(7) Å, in which the inner (Cu1) and outer (Cu2) copper(II) atoms are located in square‐planar and square‐pyramidal geometries, respectively. To evaluate the effects of bridging ligand hydrophobicity on DNA/protein binding and potential anticancer activities, comparative studies of the reactivity towards herring sperm DNA and protein bovine serum albumin (BSA) as well as cytotoxicity of complex 1 with our previously reported complex 2 were conducted theoretically and experimentally. The results indicate that the two complexes can interact interactively with DNA, and bind to BSA via the binding sites Trp213 for 1 and Trp134 for 2. Interestingly, the in vitro anticancer activities and DNA/protein binding affinities consistently follow the order of 1 > 2.

DNA/BSA‐binding property and in vitro anticancer activity of a new dicopper(II) complex with N‐(2‐hydroxy‐5‐nitrophenyl)‐N′‐[3‐(diethylamino)propyl]oxamide as bridging ligand: Synthesis and crystal structure

A new oxamido‐bridged dicopper(II) complex formulated as [Cu2(ndpox)(bpy)(CH3OH)2]‐ (ClO4), where H3ndpox is N‐(2‐hydroxy‐5‐nitrophenyl)‐N′‐[3‐(diethylamino)propyl]oxamide; and bpy represents 2,2′‐bipyridine, was synthesized and structurally characterized using X‐ray single‐crystal diffraction and other methods. In the molecule, the endo‐ and the exo‐copper(II) ions bridged by the cis‐ndpox3− ligand are in {N3O2} and {N2O3} square‐ pyramidal environments, respectively. There is a three‐dimensional hydrogen bonding network dominated by O‐H···O and C‐H···O interactions in the crystal. The reactivity toward DNA/protein bovine serum albumin (BSA) revealed that the complex could interact with herring sperm DNA (HS‐DNA) through the intercalation mode, and effectively quench the intrinsic fluorescence of BSA via a static process. Cytotoxicity studies suggest that the complex displays selective cancer cell antiproliferative activity. The present investigation confirmed that the combined effects of both electron‐withdrawing and hydrophobic groups on the bridging ligand in the dicopper(II) complex systems can increase DNA/BSA‐binding ability and in vitro anticancer activity.

PH-Responsive Graphene Oxide-DNA Nanosystem for Live Cell Imaging and Detection.

The interaction between graphene oxide (GO) and DNA is very sensitive to the environment. For example, under acidic conditions, the affinity of GO for DNA is enhanced, weakening the capability of GO to distinguish DNAs with different conformations. This effect has impeded the development of sensitive pH biosensors based on GO-DNA nanosystems. In this work, we systematically studied the affinity between GO and i-motif forming oligonucleotides (IFOs) at different pH values and developed a herring sperm DNA (HSD) treatment method. Using this method, HSD occupies the surface of GO, compromising the attractive force of GO that is significantly enhanced under acidic conditions. As a result, the ability of GO to distinguish between "open" and "closed" IFOs is successfully generalized to a wider pH range. Finally, a pH-sensitive GO-IFO nanosystem was fabricated that showed excellent sensing ability both in vitro and for intracellular pH detection. Because the interaction between GO and DNA is the basis for constructing GO-DNA biosensors, the strategy developed in this work shows great potential to be applied in a variety of other GO-DNA sensing systems.

Ruthenium(II) complexes of aroylhydrazones: structural, electrochemical and electrostatic interactions with DNA

Four Ru(II) complexes with tridentate ligands viz. (4-hydroxy-N′-(pyridin-2-yl-ethylene) benzohydrazide [Ru(L1)(PPh3)2(Cl)] (1), N′-(pyridin-2-yl-methylene) nicotinohydrazide [Ru(L2)(PPh3)2(Cl)] (2), N′-(1H-imidazol-2-yl-methylene)-4-hydroxybenzohydrazide [Ru(L3)(PPh3)2(Cl)] (3), and N′-(1H-imidazol-2-yl-methylene) nicotinohydrazide [Ru(L4)(PPh3)2(Cl)] (4) have been synthesized and characterized. The methoxy-derivative of L3H (abbreviated as L3H*) exists in E configuration with torsional angle of 179.4° around C7-N8-N9-C10 linkage. Single crystal structures of acetonitrile coordinated ruthenium complexes of 1 and 3 having compositins as [Ru(L1)(PPh3)2(CH3CN)]Cl (1a) and [Ru(L3)(PPh3)2(CH3CN)]Cl (3a) revealed coordination of tridentate ligands with significantly distorted octahedral geometry constructed by imine nitrogen, heterocyclic nitrogen, and enolate amide oxygen, forming a cis-planar ring with trans-placement of two PPh3 groups and a coordinated acetonitrile. Ligands (L1H-L4H) and their ruthenium complexes (1–4) are characterized by 1H, 13C, 31P NMR, and IR spectral analysis. Ru(II) complexes have reversible to quasi-reversible redox behavior having Ru(II)/Ru(III) oxidation potentials in the range of 0.40–0.71 V. The DNA binding constants determined by absorption spectral titrations with Herring Sperm DNA (HS-DNA) reveal that L4H and 1 interact more strongly than other ligands and Ru(II) complexes. Complexes 1–3 exhibit DNA cleaving activity possibly due to strong electrostatic interactions while 4 displays intercalation.

Study on the interaction of anthracenyl-methyl homospermidine conjugate (ANTMHspd) with DNA by spectroscopic methods

The interaction between anthracenyl-methyl homospermidine conjugate (ANTMHspd) with herring sperm DNA was investigated by UV/vis absorption, fluorescent spectra, circular dichroism (CD) spectroscopy and 1HNMR under physiological conditions (pH=7.4). The observed hypochromism effect and fluorescence quenching of ANTMHspd by DNA, and the displacement of EB from DNA-EB system by ANTMHspd suggested that ANTMHspd might interact with DNA by the combined mode of intercalation and groove binding. Further fluorescent tests at different temperatures revealed that the quenching mechanism was a static type. The quenching constant, binding constant and thermodynamic parameter obtained from fluorescence showed that the type of interaction force included mainly hydrogen bonding and van der Waals, which promoted the binding process. The CD test revealed that ANTMHspd could cause the B to A-like conformational change while ANTMHspd is not a typical DNA intercalator. The 1H NMR tests showed that ANTMHspd partially intercalated DNA. The effect of NaCl and KI on ANTMHspd–DNA interaction provided additional evidences of intercalation. Molecular docking simulation was carried out and the docking model in silico suggested that the binding modes of ANTMHspd and DNA were groove binding and intercalation, with the anthracene moiety inserted in DNA base pairs and the polyamine chain embedded in the DNA groove.

Syntheses, crystal structures and DNA-binding studies of Cu(II) and Zn(II) complexes bearing asymmetrical aroylhydrazone ligand

Zn(II) and Cu(II) complexes with benzophenone benzoyl hydrazone (HBBH) and benzophenone salicylylhydrazone (HBSH) have been synthesized and characterized by different physico-chemical and spectroscopic techniques (UV-vis, IR and NMR). The molecular structures of these complexes [Zn(BBH)2, Cu(BBH)2 and Cu(BSH)2Cl2H2O] have also been determined by single X-ray diffraction technique. In Zn(BBH)2 and Cu(BBH)2 complexes, each ligand coordinates to metal through enol tautomeric form by azomethine-N and carbonylate-O resulting a 4-coordinate distorted tetrahedral geometry. While in Cu(BSH)2Cl2H2O, each ligand coordinates to metal through keto tautomeric form resulting distorted octahedral geometry in which two chlorine atoms occupy the axial positions. The DNA interaction propensity of the complexes with Herring sperm DNA, studied at physiological pH by spectrophotometric, spectrofluorometric, viscometric techniques and cyclic voltammetry, revealed intercalation as the possible binding mode. Fascinatingly, Cu(BSH)2Cl2H2O was found to exhibit greater binding strength than the others. A strong hyperchromism effect and a slight red shift were exhibited by all complexes. The intrinsic binding constants are of moderate values and are about 3.28 × 104 M−1, 4.73 × 104 M−1 and 5.80 × 104 M−1, respectively. Cyclic voltammetry studies of the complexes binding with DNA indicate quasireversible oxidation and reduction potentials. The results suggest that the binding affinity of complexes lies in the order Cu(BSH)2Cl2H2O > Cu(BBH)2 > Zn(BBH)2.

Synthesis, characterization, and DNA binding studies of the hematoxylin-Zn(II) complex

ABSTRACTThe binding mechanism of Hematoxylin-Zn(II) complex with Herring sperm DNA has been investigated using UV–vis and fluorescence spectroscopies and viscosity measurement. With the increase in the concentration of complex, the viscosity of DNA decreased, and the binding mode is more detailed: there is partially intercalate binding. Furthermore, besides the intercalate binding, the existence of groove binding was confirmed through the ionic strength experiment in Scatchard analysis. Thermodynamic studies provided some thermodynamic parameters: ΔrHmΘ = 1.43 × 105 J mol−1, ΔrSmΘ = 576.14 J mol−1, ΔrGmΘ303K = −3.16 × 104 J mol−1, they illustrated that the binding mechanism between HE-Zn(II) complex and hsDNA was driven mainly by entropy.