DNA Binding Properties Research Articles

Tryptamine‐Derived Schiff Bases: Potent Antimicrobial Agents and Evaluation of Cytotoxicity, ADME and DNA Binding Properties

Inspired by the fact that the introduction of indole pharmacophore in organic scaffolds could enable interesting pharmacological properties, the series of novel tryptamine‐derived Schiff bases was synthetized. Tryptamine was used as a source of indole pattern, as well as an example of biogenic amines which chemical transformations lead to the compounds with prominent biological activities. The obtained results for antimicrobial activity against a range of bacterial and fungal strains and cytotoxic activities have revealed that Schiff base TSB4 combining the tryptamine and p‐nitro aryl patterns in the structure showed better antifungal activity at low concentrations than standard drug Fluconazole, while compound TSB6 with molecular scaffold composed from tryptamine and quinoline moieties showed certain cytotoxic effect on HCT‐116 cell line with a strongly expressed selectivity about healthy fibroblast cells, MRC‐5. For these two selected compounds, additional ADME analysis and DNA interactions were performed. to obtain better insight into their pharmacokinetics and determination of binding mode for DNA molecules. As results suggested, strong binding of examined compounds to CT‐DNA was observed, while the ADME screening showed that selected compounds possess suitable physicochemical properties for oral bioavailability and druglikeness.

A novel copper(II) complex with a salicylidene carbohydrazide ligand that promotes oxidative stress and apoptosis in triple negative breast cancer cells.

We report the synthesis, characterization, anti-cancer activity and mechanism of action of a novel water-soluble Cu(II) complex with salicylidene carbohydrazide as the ligand and o-phenanthroline as the co-ligand. The synthesized complex (1) was characterized by FT-IR, EPR, and electronic spectroscopy, as well as single crystal X-ray diffraction. This compound was found to be paramagnetic from EPR spectra and X-ray crystallography revealed that the molecule crystallized in an orthorhombic crystal system. The crystal lattice was asymmetric containing two distinct binuclear copper complexes containing the Schiff base as the major ligand, o-phenanthroline as a co-ligand, two nitrate anions, and two water molecules. The Cu(II) in the first site coordinated with the enolised ligand comprising enolate O-, phenolate O-, and the imine N and N,N from o-phen. The major part of this complex exists as Cu(II) coordinated with two H2O molecules at the second site with nitrate acting as the counter anion. However, a smaller portion of the complex exists where Cu(II) is coordinated with NO3- and H2O, and the remaining water molecule acts as lattice water. It was tested for DNA binding and cleavage properties which revealed that it binds in an intercalative mode to CT-DNA with Kb value of 1.25 × 104 M-1. Furthermore, cleavage studies reveal that the complex has potential for efficient DNA cleavage under both oxidative and hydrolytic conditions. It was able to enhance the rate of cleavage by 2.8 × 108 times. The complex shows good cytotoxicity to breast cancer monolayer (2D) as well as spheroid (3D) systems. The IC50 values for MDA-MB-231 and MCF-7 monolayer culture was calculated as 1.86 ± 0.17 μM and 2.22 ± 0.08 μM, respectively, and in (3D) spheroids of MDA-MB-231 cells, the IC50 value was calculated to be 1.51 ± 0.29 μM. It was observed that the complex outperformed cisplatin in both breast cancer cell lines. The cells treated with complex 1 underwent severe DNA damage, increased oxidative stress and cell cycle arrest which finally led to programmed cell death or apoptosis in triple negative breast cancer cells through an intrinsic pathway.

Synthesis, Characterization, and Biological Activity of New 4`-Functionalized Bis-Terpyridine Ruthenium(II) Complexes: Anti-inflammatory Activity Advances.

Ruthenium complexes incorporating 2,2':6',2''-terpyridine ligands have emerged as promising candidates due to their versatile biological activities including DNA-binding, anti-inflammatory, antimicrobial, and anticancer properties. In this study, three novel 4'-functionalized bis(terpyridine) ruthenium (II) complexes were synthesized. These complexes feature one ligand as 4-(2,2':6',2''-terpyridine-4'-yl) benzoic acid and the second ligand as either 4'-(2-thienyl)-2,2':6',2''-terpyridine, 4'-(3,4-dimethoxyphenyl)-2,2':6',2''-terpyridine, or 4'-(4-dimethylaminophenyl)-2,2':6',2''-terpyridine. Besides the chemical characterization by 1H and 13C NMR, mass spectrometry, and absorption and emission spectroscopy, the complexes were tested for their biological activity as anti-inflammatory, anticancer, and antimicrobial agents. Moreover, the toxicity of the Ru(II) complexes was assessed and benchmarked against diclofenac potassium and ibuprofen using a haemolysis assay. Biological evaluations demonstrate that these ruthenium complexes exhibit promising therapeutic potential with reduced haemolytic activity compared to standard drugs. They demonstrate substantial anti-inflammatory effects through inhibition of albumin denaturation along with moderate cytotoxicity against cancer cell lines and broad-spectrum antimicrobial activity. These findings highlight the multifaceted biomedical applications of 4'-functionalized bis(terpyridine) ruthenium (II) complexes, suggesting their potential for further development as effective and safe therapeutic agents.

Structural mechanisms of SLF1 interactions with Histone H4 and RAD18 at the stalled replication fork.

DNA damage that obstructs the replication machinery poses a significant threat to genome stability. Replication-coupled repair mechanisms safeguard stalled replication forks by coordinating proteins involved in the DNA damage response (DDR) and replication. SLF1 (SMC5-SMC6 complex localization factor 1) is crucial for facilitating the recruitment of the SMC5/6 complex to damage sites through interactions with SLF2, RAD18,and nucleosomes. However, the structural mechanisms of SLF1's interactions are unclear. In this study, we determined the crystal structure of SLF1's ankyrin repeat domain bound to an unmethylated histone H4 tail, illustrating how SLF1 reads nascent nucleosomes. Using structure-based mutagenesis, we confirmed a phosphorylation-dependent interaction necessary for a stable complex between SLF1's tandem BRCA1 C-Terminal domain (tBRCT) and the phosphorylated C-terminal region (S442 and S444) of RAD18. We validated a functional role of conserved phosphate-binding residues inSLF1, and hydrophobic residues in RAD18 that areadjacent to phosphorylation sites, both of whichcontribute to the strong interaction. Interestingly, we discovered a DNA-binding property of this RAD18-binding interface, providing an additional domain of SLF1 to enhance binding to nucleosomes. Our results provide critical structural insights into SLF1's interactions with post-replicative chromatin and phosphorylation-dependent DDR signalling, enhancing our understanding of SMC5/6 recruitment and/or activity during replication-coupled DNA repair.

Elucidation of DNA binding properties of transition metal ion complexes of curcumin: An In Vitro study

Introduction: The present work aims to synthesize, characterize, and DNA binding properties of copper, nickel, zinc, and iron complexes of a well-known polyphenol drug curcumin. The metal ion complexes of curcumin's synthesized transition metal ion complexes were characterized by UV-vis spectroscopy and FTIR. Method: The complexation of curcumin with transition metal ion complexes changes the color of the curcumin based on the metal incorporated. Moreover, the shift in the absorption maxima of curcumin metal ion complexes may confirm the formation of coordination complexes. Then, FTIR results indicated that the coordination of curcumin with metal ions in the ketone group of curcumin confirms the formation of 1:2 (M: L) complexes. Results: Then, we evaluated the DNA binding properties of synthesized metal ion complexes of curcumin using electronic absorption spectra and agarose gel electrophoresis. The results indicated that the curcumin zinc complex exhibited less DNA binding constant among the four metal ion complexes than all the other compounds tested, confirming its weak interaction. Conclusion: Moreover, all the compounds degrade plasmid DNA, confirming their DNA cleavage activity. From our findings, these compounds will pave the way for developing new anticancer drugs with less toxicity.

Heteroleptic complexes of hydrazone Scaffold of picolinoyl N- oxide and 2,4 dihydroxy phenyl moieties; evaluation of antioxidant activity, DNA and protein binding properties and in vitro antiproliferation studies

The present study deals with design and synthesis of new mononuclear Cu(II), Co(II), Ni(II) and Zn(II) metal complexes of hydrazone of 2-(2-(2,4-dihydroxybenzylidene)hydrazinecarbonyl)pyridine-1-oxide (H2L), in a view to study their potential relevance for the biological applications. Structural aspects of the title compound (H2L) and metal complexes synthesized were evaluated by spectral and analytical methods viz. 1H NMR, 13C NMR, LC-MS, FT-IR, UV–Visible, SEM, EDX, Powder XRD, ESR, TGA and DTA. Ligational properties of H2L were explored by employing pH metric equilibrium studies for recognizing metal ion binding potential donor sites, and further HyperChem 7.5 software for computing properties of frontier molecular orbitals to ascertain orientation of highest occupied molecular orbitals from which presumably electrons are donated to metal ion in complex formation. The affinity of all title compounds to bind with CT-DNA and the type of interaction, therein have been studied by conducting UV–VIS absorption and fluorescence emission titrations. The protein-binding ability of all metal complexes with two serum proteins (BSA and HSA) were explored by absorption titrations, and further fluorescence titrations for BSA binding were also performed. Antioxidant activity of the title compounds was carried out by the method of free radical scavenging using spectrophotometric technique. Additionally, cytotoxicity of all metal complexes and ligand was measured by CTG cell proliferation assay after treating them with MDA-MB-231 and SKOV-3 cell lines. The cell cycle arrest and apoptosis assay in above cell lines after treatment with title compounds were also investigated by flow cytometry. In addition, molecular docking studies at target CDK2 protein inferred binding affinity of the title compounds through non covalent bonding interactions.

Copper(II) and Zinc(II) complexes of new water-soluble Schiff base ligands and their antiproliferative properties towards mesothelioma cell line

In this work, three Schiff base ligands (HL1-HL3) containing a triphenyl phosphonium cation and their Cu(II) and Zn(II) complexes with the general formulae of [M(L)Cl2] were synthesized and their structures were characterized by spectroscopic and analytical methods. Crystal structure of complex [Zn(L1)Cl2] was determined. In the structure of the complex, each Zn(II) ion is four coordinated binding to phenolate oxygen and imine nitrogen atoms of the ligand L1 and two chloride atoms in approximately tetrahedral geometry. The equilibrium geometry of three Schiff base ligands (HL1-HL3) and their Cu(II) and Zn(II) complexes were calculated using the density functional theory (DFT/B3LYP) method with the 6–31++G(d,p) basis set for the C, H, Cl, N, O, P atoms and LANL2DZ for the I atom. Frontier molecular orbitals (HOMO, LUMO) analyses were conducted for the optimized geometries of the compounds, and chemical reactivity descriptors such as hardness, softness, electrophilicity, and electronegativity were examined. Additionally, the molecular electrostatic potential (MEP) of all compounds was modeled using DFT calculations. These calculations were thoroughly examined, and their implications were discussed. The ligands and their metal complexes were investigated for their DNA binding properties. The compounds showed comparable DNA binding properties to ethidium bromide (EB) and 5-fluorouracyl (5-Fu) with DNA binding constant (Kb) 1.5–6.25 × 105 M−1. The cytotoxic properties of the compounds towards HUVEC and H2452 (mesothelioma cell line) cells were investigated using an MTS assay. The IC50 values determined for HUVEC cells were found to range between 27.28 µg/mL ([Cu(L2)Cl2]) and 273.1 µg/mL ([Zn(L2)Cl2]), while in H2452 cells, they varied from 39.48 µg/mL ([Cu(L2)Cl2]) to 319.3 µg/mL ([Zn(L3)Cl2]). The compounds HL1, HL3, and [Zn(L3)Cl2] exhibited antioxidant activity at the highest concentration (750 µg/mL) only, while [Zn(L1)Cl2], HL2, [Zn(L2)Cl2], [Cu(L2)Cl2], and [Cu(L3)Cl2] showed antioxidant activity at 250 µg/mL.

Theoretical Study of the Effects of Different Coordination Atoms (O/S/N) on Crystal Structure, Stability, and Protein/DNA Binding of Ni(II) Complexes with Pyridoxal-Semi, Thiosemi, and Isothiosemicarbazone Ligand Systems

Nickel transition metal complexes have shown various biological activities that depend on the ligands and geometry. In this contribution, six Ni(II) nitrate complexes with pyridoxal-semi, thiosemi, and isothiosemicarbazone ligands were examined using theoretical chemistry methods. The structures of three previously reported complexes ([Ni(PLSC)(H2O)3]∙2NO3−, [Ni(PLTSC)2] ∙2NO3−∙H2O, and [Ni(PLITSC)(H2O)3]∙2NO3−) were investigated based on Hirshfeld surface analysis, and the most important stabilization interactions in the crystal structures were outlined. These structures were optimized at the B3LYP/6-311++G(d,p)(H,C,N,O,(S))/LanL2DZ(Ni) level of theory, and the applicability was checked by comparing theoretical and experimental bond lengths and angles. The same level of theory was applied for the optimization of three additional structures, ([Ni(PLSC)2]2+, [Ni(PLTSC)(H2O)3]2+, and [Ni(PLITSC)2]2+). The interactions between selected ligands and Ni(II) were examined using the Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) approaches. Particular emphasis was placed on interactions between oxygen, sulfur, and nitrogen donor atoms and Ni(II). Human Serum Albumin (HSA) and the DNA-binding properties of these complex cations were assessed using molecular docking simulations. The presence of water molecules and various substituents in the thermodynamics of the processes was demonstrated. The results showed significant effects of structural parameters on the stability and reactivity towards important biomolecules.

Histones and histone variant families in prokaryotes

Histones are important chromatin-organizing proteins in eukaryotes and archaea. They form superhelical structures around which DNA is wrapped. Recent studies have shown that some archaea and bacteria contain alternative histones that exhibit different DNA binding properties, in addition to highly divergent sequences. However, the vast majority of these histones are identified in metagenomes and thus are difficult to study in vivo. The recent revolutionary breakthroughs in computational protein structure prediction by AlphaFold2 and RoseTTAfold allow for unprecedented insights into the potential function and structure of previously uncharacterized proteins. Here, we categorize the prokaryotic histone space into 17 distinct groups based on AlphaFold2 predictions. We identify a superfamily of histones, termed α3 histones, which are common in archaea and present in several bacteria. Importantly, we establish the existence of a large family of histones throughout archaea and in some bacteriophages that, instead of wrapping DNA, bridge DNA, thereby diverging from conventional nucleosomal histones.

Sustained use of antimutagenic bioactives having affinity with DNA minor groove could prevent in vitro neoplastic induction

IntroductionStudies on the antimutagenic and anti-neoplastic effect of dietary ingredients can be useful in developing nutraceuticals for preventing neoplastic induction. In the current study the query whether food rich in antimutagenic potential equally suppress the neoplastic induction, was addressed, with potential mechanism of action. MethodsThe antimutagenic activity was evaluated using the TK6 gene mutation assay, assessing the reduction in ethyl methanesulfonate (EMS)-induced mutation in presence of vegetable extracts. The anti-⁠neoplastic activity was assessed using the C3H/⁠10T1/⁠2 cell transformation assay, quantifying the inhibition of anchorage-independent growth and type III foci formation. The prominent compounds in the vegetable extract were characterised using gas chromatography-⁠mass spectrometry (GC-⁠MS), and their interactions with DNA were predicted using molecular docking. ResultsAmong the vegetable extracts, garlic exhibited the most potent antimutagenic and anti-neoplastic effects, followed by spinach and beans. Garlic extract exhibited significantly high antimutagenic potential (59±3%), and anti-neoplastic activity in the terms of inhibition of anchorage independence (65±3%) and inhibition of type III foci formation (90±5%). GC-MS analysis of garlic extract identified abundant organosulphur compounds, terpenes, and terpenoids. Molecular docking studies suggested that these compounds bind to the DNA minor groove with binding energies ranging from −⁠4.3 to −⁠7.21 kcal mol-⁠1. DiscussionThe antimutagenic and antineoplastic activities showed a positive correlation (r=0.92–0.93), where garlic extract showed the highest potential. The DNA binding properties of the prominent compounds in garlic extract suggests a potential mechanism of action involving interference with carcinogen activity and subsequent prevention of gene dysregulation.

Synthesis, kinetics, mechanisms, and bioactivity evaluations of a novel Zn(ii) complex.

Zn(ii)-based anticancer drugs can be suitable alternatives to conventional Pt(ii)-based drugs because of the unique chemical properties of Zn(ii) and low toxicity. In this study, a new hexadentate and heteroleptic Zn(ii) complex ([Zn(bpy)2(OAc)2], 1) was prepared with a conventional N,N-donor ligand (2,2'-bipyridine) and a leaving group (OAc) and characterized via ESI-MS, UV-Vis, and FT-IR spectroscopy. Kinetic and mechanistic investigations of 1 were performed using two biologically relevant ligands (dl-penicillamine and l-cysteine) to understand its selectivity and reactivity. Substitution reactions were determined to be two-step processes in the associative activation mode. Bioactivity studies of 1 revealed moderate to strong DNA-binding, cleaving ability, and antimicrobial properties.

In vitro and in silico DNA interaction studies of a series of 3-carboxamide-4-quinolone derivatives prepared from an one-pot stepwise synthesis (OPSS) method

The 3-carboxamide-4-quinolone framework is highly regarded in the fields of Medicinal and Bioorganic Chemistry mainly due to its widespread bioactive properties. This versatile scaffold allows for the development of compounds with various pharmacological effects. In this sense, the present work explores a novel one-pot stepwise (OPPS) method for synthesizing fifteen 3-carboxamide-4-quinolone derivatives, some of which exhibit antitumor profiles in previous works. These compounds were synthesized using the OPPS methodology with yields ranging from 35 % to 88 %, streamlining the synthetic process and reducing solvent usage. Furthermore, interaction studies with calf-thymus DNA were done by UV–Vis absorption and steady-state fluorescence measurements combined with molecular docking calculations. Compounds 10a-b, 10d-g, 10k, and 10n were selected for the CT-DNA interaction assays, from which it was possible to demonstrate their DNA-binding property through peripheral secondary interactions. Molecular docking results suggested van der Waals and hydrogen bonds as the main binding forces responsible for the interactive profile between the nucleobases and the 3-carboxamide-4-quinolone derivatives. All these results unveiled promising insights into their role as DNA replication inhibitors, highlighting their potential in developing antiproliferative drugs.

ΔNp63 bookmarks and creates an accessible epigenetic environment for TGFβ-induced cancer cell stemness and invasiveness

Backgroundp63 is a transcription factor with intrinsic pioneer factor activity and pleiotropic functions. Transforming growth factor β (TGFβ) signaling via activation and cooperative action of canonical, SMAD, and non-canonical, MAP-kinase (MAPK) pathways, elicits both anti- and pro-tumorigenic properties, including cell stemness and invasiveness. TGFβ activates the ΔNp63 transcriptional program in cancer cells; however, the link between TGFβ and p63 in unmasking the epigenetic landscape during tumor progression allowing chromatin accessibility and gene transcription, is not yet reported.MethodsSmall molecule inhibitors, including protein kinase inhibitors and RNA-silencing, provided loss of function analyses. Sphere formation assays in cancer cells, chromatin immunoprecipitation and mRNA expression assays were utilized in order to gain mechanistic evidence. Mass spectrometry analysis coupled to co-immunoprecipitation assays revealed novel p63 interactors and their involvement in p63-dependent transcription.ResultsThe sphere-forming capacity of breast cancer cells was enhanced upon TGFβ stimulation and significantly decreased upon ΔNp63 depletion. Activation of TGFβ signaling via p38 MAPK signaling induced ΔNp63 phosphorylation at Ser 66/68 resulting in stabilized ΔNp63 protein with enhanced DNA binding properties. TGFβ stimulation altered the ratio of H3K27ac and H3K27me3 histone modification marks, pointing towards higher H3K27ac and increased p300 acetyltransferase recruitment to chromatin. By silencing the expression of ΔNp63, the TGFβ effect on chromatin remodeling was abrogated. Inhibition of H3K27me3, revealed the important role of TGFβ as the upstream signal for guiding ΔNp63 to the TGFβ/SMAD gene loci, as well as the indispensable role of ΔNp63 in recruiting histone modifying enzymes, such as p300, to these genomic regions, regulating chromatin accessibility and gene transcription. Mechanistically, TGFβ through SMAD activation induced dissociation of ΔNp63 from NURD or NCOR/SMRT histone deacetylation complexes, while promoted the assembly of ΔNp63-p300 complexes, affecting the levels of histone acetylation and the outcome of ΔNp63-dependent transcription.ConclusionsΔNp63, phosphorylated and recruited by TGFβ to the TGFβ/SMAD/ΔNp63 gene loci, promotes chromatin accessibility and transcription of target genes related to stemness and cell invasion.

Analysis of the DNA-binding properties of TGF-β-activated Smad complexes unveils a possible molecular basis for cellular context-dependent signaling.

Transforming growth factor-β (TGF-β) is a pleiotropic cytokine that modulates a wide variety of cellular responses by regulating target gene expression. It principally transmits signals via receptor-activated transcription factors Smad2 and Smad3, which form trimeric complexes with Smad4 upon activation and regulate gene expression by binding to genomic DNA. Here, we examined the mechanisms by which TGF-β regulates the transcription of target genes in a cell context-dependent manner by screening a double-stranded DNA oligonucleotide library for DNA sequences bound to endogenous activated Smad complexes. Screening was performed by cyclic amplification of selected targets (CASTing) using an anti-Smad2/3 antibody and nuclear extracts isolated from three cell lines (A549, HepG2, and HaCaT) stimulated with TGF-β. The preference of the activated Smad complexes for conventional Smad-binding motifs such as Smad-binding element (SBE) and CAGA motifs was different in HepG2 than in the other two cell lines, which may indicate the distinct composition of the activated Smad complexes. Several transcription factor-binding motifs other than SBE or CAGA, including the Fos/Jun-binding motifs, were detected in the enriched sequences. Reporter assays using sequences containing these transcription factor-binding motifs together with Smad-binding motifs indicated that some of the motifs may be involved in cell type-dependent transcriptional activation by TGF-β. The results suggest that the CASTing method is useful for elucidating the molecular basis of context-dependent Smad signaling.

Metal-free internal nucleophile-triggered domino route for synthesis of fused quinoxaline [1,4]-diazepine hybrids and the evaluation of their DNA binding properties

An unprecedented metal-free synthesis of fused quinoxaline 1,5-disubstituted-[1,4]-diazepine hybrids have been reported under mild conditions through a domino intermolecular SNAr followed by an internal nucleophile-triggered intramolecular SNAr pathway. Our strategy offers the flexibility for the introduction of a broad variety of functionalities at the N-1 position of fused diazepine moiety by using suitable diamine tails to design structurally diverse scaffolds. The DNA binding properties of representative quinoxaline diazepine hybrids were studied using UV–vis absorbance and EtBr displacement assay and were found to be governed by the functionalities at the N-1 position. Interestingly, compound 11f containing the N-1 benzyl substitution demonstrated significant DNA binding (KBH ∼ 2.15 ± 0.25 × 104 M−1 and Ksv ∼ 12.6 ± 1.41 × 103 M−1) accompanied by a bathochromic shift (Δλ ∼ 5 nm). In silico studies indicated possible binding of diazepine hybrid 11f at the GC-rich major groove in the ct-DNA hexamer duplex and showed comparable binding energies to that of ethidium bromide. The antiproliferative activity of compounds was observed in the given order in different cell lines: (HeLa > HT29 > SKOV 3 > HCT116 > HEK293). Lead compound 11f demonstrated maximum cytotoxicity (IC50 value of 13.30 μM) in HeLa cell lines and also caused early apoptosis-mediated cell death in cancer cell lines. We envision that our work will offer newer methodologies for the construction of fused quinoxaline 1,5-disubstituted-[1,4]-diazepine class of molecules.

Synthesis, structural characterization, electrochemical, photophysical and DNA binding properties of two Anderson POM-based hybrids

In this article, two new hybrid compounds Na(C2H7N4O)2[AlMo6(OH)6O18]·2H2O (DA) and (C4H13N5)[HAlMo6(OH)6O18].10H2O (MA) were obtained from the reaction of the organic ligands (dicyandiamide and metformin) with Anderson polyoxometalate (POM) in the water solution. Anderson POM based hybrids DA and MA were characterized by the spectroscopic methods such as, FTIR, UV–vis, photoluminescence. Crystal structures of the hybrid compounds were determined by single crystal X-ray diffraction studies. In the crystal structure of MA, Anderson type polyoxometalate anions are linked by OH·····O and NH·····O hydrogen bonds forming 2D supramolecular structure in which there are solvent accessible voids. In the structure of DA, type polyoxometalate anions are connected by Na+ ions forming 2D coordination polymer type structure. The electrochemical properties of the Anderson POM and its hybrids DA and MA were investigated in the range of -2 — (+2) V, range. It is seen that Anderson type POM has two oxidation and reduction potentials. These redox processes are reversible at the 0.3 and -0.75 V (Ipa/Ipc). On the other hand, the oxidation and reduction processes of the Anderson POM based hybrids DA and MA have shifted to the lower regions and all processes are irreversible process in this potential range. Thermal properties of the hybrids DA and MA were investigated in the 20—800 °C temperature range. UV–Vis spectral and viscosity measurements revealed that hybrids DA and MA interact with DNA via groove mode.

D-π-A type fluorescent dyes: Effect of π-bridge units on optical and G4 DNA binding properties

Fluorescent solvatochromic dyes that are sensitive to the nature of local microenvironmental, have been explored as probes in applications ranging from the imaging biomolecules to understanding of basic biomolecule functions. To expand the scope of fluorescent solvatochromic dyes for G-quadruplex (G4) DNA structures, and to illustrate the relationship between structure and properties, three newly designed D-π-A type fluorescent dyes were synthesized by introducing diarylimidazole to carbazole skeleton linked to benzene, furan or thiophene π-conjugated bridge and connected with pyridinium acceptor, respectively. Their structural characteristics, optical properties, and G4 DNA binding properties were discussed in detail. In general, the incorporation of furan and thiophene as π-conjugated bridges leads the better conjugation and molecular coplanarity with more efficient intramolecular charge transfer (ICT) effect compared with benzene bridge. The fluorescence intensities induced upon interaction were found that TP-6 with thiophene π-conjugated bridge had the strongest response toward G4 DNAs. In addition, the application of this dye as a fluorescent agent for living cell imaging was also demonstrated.

In silico research on Novel Derivatives of N-(Acetylphenyl)-N-Ferrocenylmethyl-3-nitroaniline as DNA Binding Agents: Using Diverse Computational Methods, including Molecular Docking and ADME/Toxicity Assessment

This study presents an in silico investigation into the potential DNA binding properties of novel derivatives of N-(Acetylphenyl)-N-Ferrocenylmethylnitroaniline using different computational techniques, including molecular docking and ADME/Toxicity assessment, we explored the interaction between these derivatives and DNA. The results reveal promising candidates with strong binding affinities to DNA, substantiated by robust electrostatic interactions. Furthermore, our study sheds light on the ADME and toxicity profiles of these compounds, providing insights into their pharmacological potential. These findings offer valuable insights into the design and development of DNA-binding agents with potential applications in various biomedical fields.

Charge transfer interaction dynamics between 6-Aminoindole and picric acid: Synthesis, spectrophotometric, characterization, computational, DNA binding, and anticancer properties

The charge transfer complex (CT) chemistry is studied between electron donor 6-Aminoindole (AMI) and electron acceptor Picric acid (PA) at 25 °C, in an acetonitrile medium by using UV–Visible absorption spectroscopy. The molecular ratio of the CT complex was determined to be 1:1 by using jobs variation and spectrophotometric titration processes. To assess the stability constant (KCT), and molar extinction coefficient (ƐCT) by using the Benesi-Hildebrand equation. These outcomes reveal that the synthesized CT complex is highly stable. The thermodynamic study is carried out in different temperatures (20-45 °C), and these results indicate increases the stability with increasing temperature. The CT complex structure was analyzed by FT-IR, 1H NMR, and 13C NMR. The surface morphology and elemental composition were identified by the SEM-EDX technique. The crystalline nature was analyzed by powdered XRD investigation. The CT complex has been screened for DNA binding and invitro cytotoxicity. The DNA binding constant value (2.3 × 105 M−1) and in vitro cytotoxicity test results on HeLa, suggest that it could be used as a potential medicinal drug in the future. Finally, the geometry optimizations were carried out by the DFT with the wB97XD method and 6-31+G(d,p) basis set. Here we investigated different parameters like bond parameters, NBO analysis, FMO analysis, DOS, PDOS, and computed electronic spectra. The computational analysis provided additional support for the experimental CT complex formation.

Donepezil-Squaric Acid Hybrid: Synthesis, Characterization and Investigation of Anticholinesterase Inhibitory, DNA Binding and Antioxidant Properties

A novel donepezil-squaric acid (DS) hybrid compound was designed, synthesized and biologically evaluated as multi-target-directed ligands against neurodegenerative disease by fusing a fragment of donepezil (D) and squaric acid (S). This study focuses on investigating the binding mechanism of double-stranded fish sperm DNA (Fsds-DNA) with DS and S. The interaction between DS and S with Fsds-DNA was explored using spectrophotometric and viscometric methods. Besides, DNA binding constants (Kb) were determined. The results reveal that DS binds to Fsds-DNA via the minor groove binding mode. The hybrid molecule demonstrates potent inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Furthermore, it exhibits significant antioxidant activity, surpassing the scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals compared to squaric acid alone. In conclusion, these results suggest that the hybrid molecule may serve as a potential multifunctional agent for the treatment of Alzheimer’s disease.