Calf Thymus DNA Research Articles

Silver(I) pyridinyl complexes with benzothiazole, thiophene, and furan moieties: DNA/protein-binding, antibacterial, antioxidant, and anticancer studies.

We have synthesized and characterized nine Ag(I) complexes of Schiff bases containing thiophene, furan, and pyridine moieties for in vitro antibacterial, antioxidant, anticancer activities, and DNA/bovine serum albumin(BSA) binding studies. Based on the analytical and spectral analyses, a linear geometry was proposed for all the Ag(I) complexes, except for one (with the furan moiety), which formed a distorted T-shaped geometry. UV-vis absorption studies on the interactions of calf thymus-DNA (CT-DNA) with the nine Ag(I) complexes pointed to an intercalative binding mode. With a binding constant Kb of 3.75 × 105 M-1 , the complex bearing a benzothiazole moiety (1) interacted stronger with CT-DNA than the rest of the complexes. Fluorescence spectroscopic data revealed that the complexes had a modest binding affinity for BSA through static quenching. The complexes displayed good antioxidant properties, especially those with a benzothiazole moiety. Notable antibacterial activities against methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae were observed for complexes with the furan and thiophene moieties. The in vitro anticancer studies of selected complexes against three cancer cell lines showed that the complexes were more effective against the inhibition of the growth of cervical cancer cells relative to cisplatin.

The melting curves of calf thymus-DNA are buffer specific

The specific effects of salts (strong electrolytes) on biomolecular properties have been investigated for more than a century. By contrast, the specific role of pH buffers (weak electrolytes and their salts) has usually been ignored. Here, specific buffer effects on DNA thermal stability were evaluated by measuring the melting curve of calf thymus DNA through UV–vis spectroscopy. The study was carried out using phosphate, Tris, citrate and cacodylate buffers at fixed pH 7.4 at concentrations varying systematically in the range 1–600 mM. DNA stability increases with buffer concentration and is influenced specifically by buffer type. To interpret empirical data, a theoretical model was applied with parameters quantifying the impact of buffer on the DNA backbone charge. Comparing the buffer effects via buffer ionic strength rather than buffer concentration, we find that the buffers stabilize DNA in the order Tris > cacodylate > phosphate > citrate.

Elucidating the interaction of antidepressant drug paroxetine with ct-dsDNA: A comparative study by electrochemical, spectroscopic, and molecular docking approaches

This study is designed to investigate the interaction of phenylpiperidine derivative drug paroxetine, which is an effective serotonin reuptake inhibitor and biomolecules through electrochemical, fluorescence spectroscopy, and molecular docking methods. The interaction between paroxetine and biomolecules was investigated by differential pulse voltammetry according to the decrease in deoxyguanosine anodic oxidation signal of double-stranded calf thymus DNA. Fluorescence spectroscopy studies were performed by titrating paroxetine against double-stranded calf thymus DNA solution at four different temperatures. The fluorescent results showed that paroxetine had a great affinity to bind with double-stranded calf thymus DNA. Interaction studies demonstrate that paroxetine binds to double-stranded calf thymus DNA via intercalation binding mode, and the binding constant values ​​were calculated as 7.24 × 104 M−1 and 1.52 × 104 M−1 at 25 °C, based on voltammetric and spectroscopic results, respectively. Moreover, with the aim of elucidating the interaction mechanism between paroxetine and double-stranded calf thymus DNA, electrochemical and fluorescence spectroscopy studies along with molecular docking analysis were made.

In Vitro and Computational Approaches to Untangle the Binding Mechanism of Galangin with Calf Thymus DNA.

Flavonoids have potential applications in the nutraceutical, medicinal, pharmaceutical and cosmetic fields. The binding of flavonoids with DNA could unravel essential information required for the design of novel and effective chemical agents. The present paper describes the interaction of a flavonoid and a potent anticancer drug, galangin (GAL) with calf thymus DNA (ct-DNA) by fluorescence, UV absorption, melting studies, viscosity measurements and molecular docking studies. A hyperchromic effect was noticed in the absorption spectra of ct-DNA in the presence of the GAL system, indicating the presence of a groove mode of binding. Furthermore, GAL persuaded the minor changes in ct-DNA viscosity, indicating a non-intercalative mode of binding. Fluorescence studies revealed that the GAL quenched the fluorescence intensity of ct-DNA-Hoechst, thereby indicating the interaction between GAL and ct-DNA. Fluorescence results obtained at 298, 308 and 318K revealed that the fluorescence quenching of ct-DNA-Hoechst-GAL occurred through the static quenching mechanism. Thermodynamic parameters for ct-DNA-Hoechst-GAL were computed and suitable conclusions were drawn. The changes noticed in the conformation of ct-DNA upon interaction with GAL were evaluated in terms of molar ellipticity. It indicated a plausible interaction between ct-DNA and GAL. The molecular docking studies also confirmed the groove mode of binding in the ct-DNA-GAL system. Thus, this work helped to unravel the binding mechanism between GAL and ct-DNA.

DNA/protein binding and anticancer activity of ruthenium (II) arene complexes based on quinoline dipyrrin

Arene ruthenium complexes [(η6–arene)Ru(L)Cl] (η6–arene = benzene, R1; p-cymene, R2) containing the chelating ligand (2–chloro–3–(di(1H–pyrrol–2–yl)methyl)quinoline) (L) have been synthesized and carefully characterized by various studies (1H and 13C NMR, IR, ESI–MS, UV–vis). The structure of R1 has been verified by X-ray single crystal analyses. Binding of the complexes with calf thymus DNA (CT–DNA) has been investigated by absorption titration, ethidium bromide (EB) displacement and viscosity measurements. Experimental binding constants (5.1 × 104 M−1, R1; 5.7 × 104 M−1, R2) suggested appreciable bonding of the complexes with CT–DNA. Fluorescence, synchronous and 3D fluorescence spectroscopic studies showed that complexes strongly bind with bovine serum albumin. Intercalative interaction of the complexes with DNA has been further supported by DFT studies. Our studies have shown potential anticancer activity of both the complexes R1 and R2 against T cell lymphoma. Among these complexes R2 showed better anticancer activity relative to R1 (IC50, R1, 30 μM and R2, 20 μM).

Surface-enhanced Raman scattering of DNA molecules on silver electrodes modified with silver nanoparticles

High-quality surface-enhanced Raman spectra (SERS) of calf thymus DNA, apple single-stranded DNA, and rice single-stranded DNA are obtained by using rough silver electrodes modified with silver nanoparticles as the substrate. The appearance of fruitful Raman-active modes enables to identify the fine vibrational modes of DNA molecules of which the normal Raman spectra are not easy to be measured. It is concluded that the silver electrode modified by silver nanoparticles is a highly sensitive SERS substrate for DNA analysis, due to the uniformly aligned silver nanoparticles in combination with additional contributions of electrode potentials. Furthermore, the SERS spectra of these DNA molecules at varying potential conditions also provide information on the adsorption behavior of these DNA molecules on the silver. It is anticipated that the DNA molecules may tend to lie flat on the nanosilver surface; with increasing negative potentials, the spectra exhibit dramatic fluctuation, which could be associated with interface oxidation and changes of the adsorption behaviors in view of the different hydrophobicity/hydrophilic nature and electrostatic interactions of the phosphate base and the electrode surface.

Quantitative structure-toxicity relationships of halobenzoquinone isomers on DNA reactivity and genotoxicity

Halobenzoquinones (HBQs) are an emerging class of drinking water disinfection byproducts that have been predicted as bladder carcinogens. However, data on the genotoxicity of HBQs are still scarce. This study performed a quantitative structure-toxicity relationship (QSTR) analysis of HBQ isomers on DNA reactivity and genotoxicity. The interaction of HBQs with calf thymus DNA (ct-DNA) was studied using multi-spectroscopic and molecular docking techniques. UV–Vis absorption spectra observed a significant hyperchromic effect with the increase of HBQ concentration. The fluorescence intensity of both probe-ct-DNA decreased with the increasing concentration of HBQs, indicating that the interaction mode between each HBQs and DNA was quite complicated, and there were both minor groove binding and intercalation binding. Molecular docking showed that HBQs interacted with DNA predominantly via hydrogen bond at guanine-rich areas in the minor groove of DNA. The genotoxicity of HBQs on human hepatocytes (L-02) was evaluated by micronucleus test, and the results showed that HBQs could cause significant chromosomal damage. The rank order of HBQ isomers on DNA reactivity and genotoxicity was 2,5-HBQs > their corresponding 2,6-HBQs. QSTR analysis found that dipole moment is the key structural descriptor influencing both DNA reactivity and genotoxicity of HBQ isomers. This study suggested that HBQs have caused genotoxicity which was influenced by their isomeric effects, warranting a comprehensive understanding of the genotoxic and carcinogenic risks associated with HBQs exposure.

Equilibrium, DNA binding, docking, and antimicrobial studies of Ni(II) and Cu(II) chelates with 1‐(4′‐nitrobenzoyl)‐3‐thiosemicarbazide

Ni(II) and Cu(II) chelates of 1‐(4′‐nitrobenzoyl)‐3‐thiosemicarbazide (PNBTSC, HL) were synthesized and characterized by liquid chromatography‐mass spectrometry (LC–MS), thermogravimetric analysis (TGA), infra‐red (IR), UV–visible, and electron spin resonance (ESR) spectral techniques, which revealed the tetragonally distorted octahedral geometry around the central metal ion in both the chelates. The kinetic and thermodynamic properties were calculated using the Coats–Redfern relation. Thermal decomposition processes of chelates indicate the thermally stability of the chelates. The optimized molecular geometry, atomic charges, energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), and energy gap 0.11203 eV of HL have been studied by density functional theory (DFT) calculations, which revealed the soft nature and high reactivity of the compound. Equilibrium studies of the 1‐(4‐nitrobenzoyl)‐3‐thiosemicarbazide with Ni(II) ion in 70% v/v DMF‐water medium have been evaluated. The pKa value of HL was found to be 7.1, and the values indicated the formation of 1:1 and 1:2 chelates in solution. DNA binding affinities of synthesized metal chelates with calf thymus DNA using UV absorption spectroscopy, spectro‐fluorimetry, and viscosity measurements revealed hypochromism and intercalative mode of binding. The Kb values from the absorption studies are 5.00 × 106 and 3.33 × 106 M−1, and Ksv values from fluorescence studies are 0.108 and 0.395 M−1 for chelates 1 and 2, respectively. The cleavage of supercoiled pBR33 DNA without any additives was studied using gel electrophoresis method which exhibited hydrolytic cleavage of plasmid DNA. Molecular docking studies carried out for the complexes also inferred intercalative mode of binding with DNA. The inhibition constants for HL, 1, and 2 are 107.09, 21.66, and 184.45 μM, respectively. Ligand and its metal chelates screened for antimicrobial activity against Gram positive and Gram negative bacteria revealed higher activity in chelates.

Metal ion induced changes in the structure of Schiff base hydrazone chelates and their reactivity effect on catalytic benzyl alcohol oxidation and biological assays

Divalent para-magnetic copper(II) and iron(II) chelates of Schiff base isatin hydrazone derivative are synthesized and characterized, as CuLONOCl and Fe(LONO)2, respectively. With different stoichiometric ratios (molar ratios) of 1: 1 and 1: 2 of Cu2+ or Fe2+ ion to the ligand (HLONO), both chelates are prepared with distorted square planar and octahedral structures, respectively. The catalytic action of both CuLONOCl and Fe(LONO)2 is examined in the homogeneous oxidation benzyl alcohol using H2O2 to benzaldehyde (the selective product). All studied compounds involved in the antimicrobial and anticancer studies and also against the ctDNA. Catalytically, their optimization is progressed within the influence of temperature, time and solvent. CuLONOCl manifests an optimized catalytic atmosphere for the yield percentage of benzaldehyde (92%) at 70°C after 4 h, whereas, Fe(LONO)2 displays less catalytic action with less yield (88%) after 3 h at 90°C. The variation in their structure and central metal ion assign to understand the difference in their catalytic potentials. The proposed mechanism for the oxygenation process based on electron-oxygen transfer steps.In the biological studies, CuLONOCl displays more action against some common microbes (bacteria and fungi) and cancers growth compared to that of Fe(LONO)2. The role of M2+ ion in its complex and its geometries illustrate their utility in such biological studies within Tweedy's chelation theory. Their interaction with ctDNA (calf thymus DNA) is aimed to represent the impact of Cu2+ and Fe2+ ions in the complexing agents with the influence of their structures through the changes and shifts of spectroscopic the viscosity investigations. Their interaction with ctDNA is illustrated spectroscopically according to the derived values of the binding constants, Kb, and the negative Gibbs’ free energy, ΔGb≠.

Pathogenic and Commensal Gut Bacteria Harboring Glycerol/Diol Dehydratase Metabolize Glycerol and Produce DNA-Reactive Acrolein.

Bacteria harboring glycerol/diol dehydratase (GDH) encoded by the genes pduCDE metabolize glycerol and release acrolein during growth. Acrolein has antimicrobial activity, and exposure of human cells to acrolein gives rise to toxic and mutagenic responses. These biological responses are related to acrolein's high reactivity as a chemical electrophile that can covalently bind to cellular nucleophiles including DNA and proteins. Various food microbes and gut commensals transform glycerol to acrolein, but there is no direct evidence available for bacterial glycerol metabolism giving rise to DNA adducts. Moreover, it is unknown whether pathogens, such as Salmonella Typhymurium, catalyze this transformation. We assessed, therefore, acrolein formation by four GDH-competent strains of S. Typhymurium grown under either aerobic or anaerobic conditions in the presence of 50 mM glycerol. On the basis of analytical derivatization with a heterocyclic amine, all wild-type strains were observed to produce acrolein, but to different extents, and acrolein production was not detected in fermentations of a pduC-deficient mutant strain. Furthermore, we found that, in the presence of calf thymus DNA, acrolein-DNA adducts were formed as a result of bacterial glycerol metabolism by two strains of Limosilactobacillus reuteri, but not a pduCDE mutant strain. The quantification of the resulting adducts with increasing levels of glycerol up to 600 mM led to the production of up to 1.5 mM acrolein and 3600 acrolein-DNA adducts per 108 nucleosides in a model system. These results suggest that GDH-competent food microbes, gut commensals, and pathogens alike have the capacity to produce acrolein from glycerol. Further, the acrolein production can lead to DNA adduct formation, but requires high glycerol concentrations that are not available in the human gut.

Multi-spectroscopic characteristics of olive oil-based Quercetin nanoemulsion (QuNE) interactions with calf thymus DNA and its anticancer activity

Several types of biological functions have been reported for Quercetin, such as antioxidant and anticancer activities. The current study aimed to improve the solubility and stability of Quercetin’s nanoemulsions (QuNEs) produced under polar physiologic conditions and to clarify Quercetin’s interaction properties with calf thymus DNA (ctDNA) in its released form. The cytotoxicity of QuNE was analyzed by measuring the MTT assay in MCF-7 cells and caspase-9 gene expression in the HePG2 liver cancer cell line. Also, the ABTS antioxidant assay was performed for evaluating QuNE’s antioxidant activity. QuNE’s interaction with ctDNA was evaluated via running RLS and CD spectroscopy, viscometry, thermal denaturation, thermodynamic parameters (Van’t Hoff and Stern-Volmer diagrams), and molecular docking methods. The QuNE-released Quercetin significantly reduced viability of MCF-7 cells and induced caspase-9 up-regulation in HepG2 cancer cells. Further, compared with unreleased Quercetin, QuNE particles made complexes with ctDNA through hydrophobic interactions. The ΔH0, ΔS0, and binding constant (BC) indices for QuNE-ctDNA were measured at 68.36 KJ.mol−1, 308.42 J.mol-1K−1, and 0.04 × 104 and 2.49 × 104 M−1, respectively. Further, high antioxidant activity was measured for QuNE. QuNE was detected as the DNA groove binder agent. Considering QuNE’s ability in releasing Quercetin near ctDNA, it can be potentially used as an appropriate delivery transporting system which can successfully interact with DNA molecules in a groove binding manner to induce apoptotic effects.

Interaction of MnTOEtPyP4 porphyrin with DNA

The binding of water-soluble meso-tetra-(4N-oxyethylpyridyl) porphyrin (H2TOEtPyP4) and its manganese (III) derivative (MnTOEtPyP4) with calf thymus DNA have been quantitatively studied using UV/Vis spectrophotometry, Circular Dichroism (CD), thermal melting curves and viscometry. The results show, that porphyrins interact with DNA via one binding mode at low relative concentrations (r) and two binding modes at high values of r. The binding constant (Kb ) and stoichiometry (n) were determined from binding isotherms for both porphyrin–DNA complexes. The thermal melting analysis indicates that the double-helical structure of DNA molecules is stabilizing in presence of studied porphyrins. At certain concentrations of porphyrin, two-stage melting curves were observed, which indicates the existence of two different binding modes. Obtained results show that MnTOEtPyP4 associates with DNA duplex via outside binding mode. Communicated by Ramaswamy H. Sarma

Gelation Properties and Drug Release Kinetics of a Thermoreversible Hydrogel as a Drug Carrier

Pluronic F-127 (PF-127) is a thermoreversible hydrogel that is a promising candidate for drug delivery. This hydrogel has a unique property that transforms its phase between liquid and gel as the temperature changes. PF-127 can be explored as a potential drug delivery system to treat diseases due to its low toxicity and controllable, sustained drug release. This study aims to determine the optimized relationship between concentration and temperature for successful PF-127 gelation and to characterize its drug release kinetics. PF-127 powder was dissolved in a saline solution to make concentrations ranging from 10% to 30%. The temperature was increased gradually to determine the precise temperature at which each PF-127 solution at a different concentration turned to gel. Concentrations under 16% did not turn to gel at any range of temperature. From 20% to 24% concentrations, PF-127 was a liquid at room temperature, while 26% to 30% concentrations were in a gel state. To characterize the drug release kinetics of PF-127, calf thymus DNA was loaded into PF-127. It showed sustained DNA release over a prolonged period of time as opposed to an immediate burst release. Sustained release kinetics shown in our study is preferable because it may steadily release a drug at an optimal concentration, preventing toxicity from a high drug concentration while maintaining therapeutic potential. The outcomes of this study elucidate a broad application of PF-127 as a potential drug carrier.

Multi-spectroscopic, thermodynamic, and molecular docking/dynamic approaches for characterization of the binding interaction between calf thymus DNA and palbociclib

Studying the binding interaction between biological macromolecules and small molecules has formed the core of different research aspects. The interaction of palbociclib with calf thymus DNA at simulated physiological conditions (pH 7.4) was studied using different approaches, including spectrophotometry, spectrofluorimetry, FT-IR spectroscopy, viscosity measurements, ionic strength measurements, thermodynamic, molecular dynamic simulation, and docking studies. The obtained findings showed an apparent binding interaction between palbociclib and calf thymus DNA. Groove binding mode was confirmed from the findings of competitive binding studies with ethidium bromide or rhodamine B, UV–Vis spectrophotometry, and viscosity assessment. The binding constant (Kb) at 298 K calculated from the Benesi–Hildebrand equation was found to be 6.42 × 103 M−1. The enthalpy and entropy changes (∆H0 and ∆S0) were − 33.09 kJ mol−1 and 61.78 J mol−1 K−1, respectively, showing that hydrophobic and hydrogen bonds constitute the primary binding forces. As indicated by the molecular docking results, palbociclib fits into the AT-rich region of the B-DNA minor groove with four base pairs long binding site. The dynamic performance and stability of the formed complex were also evaluated using molecular dynamic simulation studies. The in vitro study of the intermolecular binding interaction of palbociclib with calf thymus DNA could guide future clinical and pharmacological studies for the rational drug scheming with enhanced or more selective activity and greater efficacy.

Microwave-assisted synthesis of functionalized carbazoles via palladium-catalyzed aryl C–H activation and study of their interactions with calf-thymus DNA

An efficient method is reported to prepare functionalized carbazoles in excellent yields under mild conditions through microwave-assisted Pd-catalyzed aryl C–H activation of 2-iodo-N-arylanilines. The use of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) as a base is found advantageous. Microwave is found beneficial to shorten the reaction time, improve yield, and reduce the amount of base and solvent consumption. Moreover, it offers the access to 4-acetylcarbazole, which was not obtained under conventional heating conditions. Interactions of carbazoles with calf-thymus DNA are investigated by monitoring the change in their photophysical properties. Experimental results hint that the dominant mode of binding of carbazoles with ct-DNA is groove binding in nature and thermodynamically favorable. The highest binding interaction is observed for 4-acetylcarbazole, and the reason behind unequal interactions for different carbazoles can be rationalized by considering the nature and position of functional groups at carbazoles which can affect H-bonding and hydrophobic interactions. Experimental results are in good agreement with molecular docking results.

Carbothioamide Based Pyrazoline Derivative: Synthesis, Single Crystal Structure, DFT/TD-DFT, Hirshfeld Surface Analysis and Biological Studies

In order to develop a potent antifungal agent, a carbothioamide-based pyrazoline derivative (3a) was synthesized. Molecular structure of compound has been confirmed using spectroscopic techniques viz. FT-IR, UV-visible, NMR, Raman spectroscopy, mass spectrometry and single crystal X-ray crystallography. Furthermore, potential antifungal activity of compound 3a was screened against three candida strains such as C. albicans, C. glabrata and C. tropicalis. For antifungal experimental validated by molecular docking study with sterol 14a-demethylase (CYP51) (PDB ID: 5JLC, 5V5Z, 6T1U) by using the Autodock Vina software. Antioxidant assay results suggested that compound possesses good radical scavenging activity against diverse free radical (DPPH). The intercalative mode of interaction of compound with Calf thymus DNA (Ct-DNA) was confirmed from spectroscopic techniques such as UV-vis., fluorescence, cyclic voltammetry and competitive assay using ethidium bromide. B3LYP technique and 6-311 ++ G (d, p) basis set were employed to optimize molecular structure and calculate wavenumbers of normal vibrational modes. A complete depiction of the intermolecular interactions on crystal surfaces is provided by Hirshfeld surface analysis, and fingerprint plots were found. The computed parameters and the experimental bond lengths and bond angles were in good agreement. The chemical shifts of the 1H and 13C-NMR spectra were estimated using the GIAO method and experimental spectra were contrasted. With the aid of the TD-DFT approach and the PCM solvent model, electronic characteristics like UV-Vis (in gas phase, ethanol and DMSO) were examined. The outcomes were then compared to experimental UV-Vis spectra.

Interaction with bioligands and in vitro cytotoxicity of a new dinuclear dioxido vanadium(V) complex

One centrosymmetric bis(μ-oxido)-bridged vanadium(V) dimer with molecular formula [(VVO2)2(pedf)2] (1) has been synthesized from the reaction of VOSO4·5H2O with a Schiff base ligand (abbreviated with pedf−) obtained from 2-acetylpyridine and 2-furoic hydrazide in methanol. Complex 1 was characterized by elemental analysis, UV–visible (UV–Vis), Fourier-transform infrared spectra (FT-IR), cyclic voltammetry (CV), electron paramagnetic resonance spectroscopy (EPR) and electrospray ionization-mass spectrometry (ESI-MS) techniques along with single crystal X-ray diffraction (SCXRD). The FT-IR spectral data of 1 indicated the involvement of oxygen and azomethine nitrogen in coordination to the central metal ion. The crystallographic studies revealed a dinuclear oxovanadium(V) complex with the Schiff base coordinated via the ONN donor set with formation of two five-membered chelate rings resulting in a distorted octahedral geometry. The interaction of 1 with calf thymus DNA (CT-DNA) was investigated by spectroscopic measurements and results suggested that the complex binds to CT-DNA via moderate intercalative mode with a binding constant (Kb) around 103 M−1. In addition, the in vitro protein binding behavior was studied by fluorescence spectrophotometric method using both bovine serum albumin (BSA) and human serum albumin (HSA) and a static quenching mechanism was observed for the interaction of the complex with both albumins that occurs with a Kb in the range (5–6) × 103 M−1. In vitro cytotoxicity of complex 1 on lung cancer cells (A549) and human skin carcinoma cell line (A431) demonstrated that the complex had a broad-spectrum of anti-proliferative activity with IC50 value of 64.2 μM and 56.2 μM.

Dioxidomolybdenum(VI) complexes of azo-hydrazones: Structural investigation, DNA binding and cytotoxicity studies

The synthesis of three new dioxidomolybdenum(VI) complexes [MoO2L1-3(X)] (1–3) {where X = EtOH for 1 and 3 and DMSO for 2} of aroylhydrazone ligands (H2L1-3) containing azobenzene moiety have been reported. H2L1-3 has been synthesized from the condensation of 5-(arylazo) salicylaldehyde derivatives with corresponding aroyl hydrazides. The azobenzene functionality was incorporated in the aroylhydrazone systems containing benzoyl, naphthyl and furyl moieties in order to explore their influence if any, on the biological properties of the corresponding molybdenum complexes. All the synthesized ligands and metal complexes were successfully characterized by elemental analysis, IR, UV–vis, NMR spectroscopy and HRMS. Redox properties of the complexes were studied by cyclic voltammetry. Molecular structures of 1–3 have been determined by X-ray crystallography. The electronic spectra of the complexes have been further analysed using time dependent density functional theory (TDDFT). DNA binding studies reveal that the complexes interact with calf-thymus DNA (CT-DNA) with binding constants in the range 104 M−1. The cytotoxicity activity of the complexes against A549 and HCT-15 cell lines has also been explored.

Imperative persistent interaction analysis of anticancer noscapine-ionic liquid with calf thymus DNA

In this study, we have shown the interaction between opium poppy alkaloid noscapine-based ionic liquid [Pip-Nos]OTf and ct-DNA using UV–visible absorption spectroscopy, fluorescence spectroscopy, CD, and computational studies. The absorption spectra showed a hypochromic shift with no shift in the absorption maxima suggesting groove or electrostatic binding. Fluorescence spectra showed an enhancement in fluorescence emission suggesting that the probable mode of binding should be groove binding. Ethidium bromide (EB) competitive and Ionic strength study showed the absence of intercalative and electrostatic modes of interaction. Further, CD analysis of ct-DNA suggested a groove binding mode of interaction of [Pip-Nos]OTf with ct-DNA. [Pip-Nos]OTf displayed a strong binding with the target ct-DNA with a molecular docking score of −41.47 kJ/mol with all 3D coordinates and full conformation. Also, molecular binding contact analyses depicted the stable binding of drug and ct-DNA with potential hydrogen bonds and hydrophobic interactions. The structural superimposition dynamics analysis showed the stable binding of [Pip-Nos]OTf with the ct-DNA model through RMSD statistics. Moreover, the ligand interaction calculations revealed the involvement of large binding energy along with a high static number of molecular forces including the hydrogen bonds and hydrophobic interactions in their complexation. These significant results report the potency of [Pip-Nos]OTf and its important futuristic role in cancer therapeutics.

Ruthenium(III) and (II) complexes containing pyridine moiety: Synthesis, crystal structure and in vitro biological evaluation

In the present study, reaction of tridentate chelating hydrazone Schiff base N'-(phenyl(pyridine-2-yl)methylidene)benzhydrazide (HL) with [RuIIICl3(PPh3)3] afforded ruthenium(III) and ruthenium(II) complexeswith the composition of [RuIII(L)Cl2(PPh3)] (1), [RuII(L)Cl(CO)(PPh3)] (2) and [RuII(Bp)Cl(CO)(PPh3)] (3) (where Bp= benzoyl pyridine) in one pot reaction. The molecular structures of synthesized complexes were examined by single crystal X-ray diffraction technique which revealed that the complexes are neutral in charge with distorted octahedral geometry. Further, the stability of the complexes were calculated theoretically and interaction of them with biomolecules resulted in change in binding energies dramatically. Complexes1–3 were evaluated for their interaction with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) using theoretical as well as spectral techniques. In addition, the in vitro cytotoxic potential of the synthesised compounds were investigated against human breast cancer cell models (MCF-7 and MDAMB-453).