Structural insights into the recognition of purine-pyrimidine dinucleotide repeats by zinc finger protein ZBTB43.

Purine-pyrimidine repeats (PPRs) can form left-handed Z-form DNA and induce DNA double-strand breaks (DSBs), posing a risk for genomic rearrangements and cancer. The zinc finger (ZF) and BTB domain-containing protein 43 (ZBTB43) is a transcription factor containing two Cys2-His2 (C2H2) and one C3H1 zinc fingers and plays a crucial role in maintaining genomic and epigenomic integrity by converting mutagenic Z-form PPRs to the B-form in prospermatogonia. Despite its importance, the molecular mechanism underlying the recognition of PPRs by ZBTB43 remains elusive. In this study, we determined the X-ray crystal structure of the ZBTB43 ZF1-3 in complex with the B-form DNA containing the CA repeats sequence. The structure reveals that ZF1 and ZF2 primarily recognize the CACA sequence through specific hydrogen-bonding and van der Waals contacts via a quadruple center involving Arg389, Met411, His413, and His414. These interactions were further validated by fluorescence-based DNA-binding assays using mutated ZBTB43 variants. Our structural investigation provides valuable insights into the recognition mechanism of PPRs by ZBTB43 and suggests a potential role for ZBTB43 in the transformation of Z-DNA to B-DNA, contributing to the maintenance of genomic stability.

Confocal image of three oxoaporphine alkaloids in cancer cell lines and their interaction with DNA by multispectroscopic and molecular docking techniques.

Dicentrinone (Di), liriodenine (Li) and lysicamine (Ly) are three natural oxoaporphine alkaloids (OAs), which revealed significant biological activity such as anticancer, anti-inflammatory and antimicrobial activities and were considered as potential lead compounds for the development of new clinical chemicals. In the present study, confocal laser scanning fluorescence microscopy observation demonstrated these three natural OAs could traverse inside of the nucleus and get an opportunity to interact with DNA. Their interaction properties with DNA were then investigated simultaneously by two spectral fluorescent probes of ethidium bromide (EB) and methyl green (MG), as well as UV-vis absorption and cyclic voltammetry measurements, and further verified by the molecular docking analysis. Results indicated Di and Li were distinctly classified as the intercalative molecules to DNA, however, Ly was confirmed with a mixed-mode binding of partial intercalation and groove affinity. Their binding ability was revealed as the follows: Di ≥ Li > Ly, which was correlated with their structural changes. Thermodynamic studies revealed the binding process of Li and Ly with ctDNA was all spontaneous, the hydrophobic interaction was the major binding force for Li-ctDNA complex, however, the interaction between Ly and ctDNA relied on both hydrophobic and hydrogen binding force. Molecular docking provided detailed computational interaction of Di, Li and Ly with DNA, which proved the intercalation binding of Li-DNA complex and Di-DNA complex stabilizing mainly by the π-π binding force, however, apart from a small quantity of π-π interaction, another binding force in the Ly-DNA complex mainly was supplied from the weaker Pi-Alkyl, hydrogen bond and Pi-Anion interactions.

Phenanthroline and phenyl carboxylate mixed ligand copper complexes in developing drugs to treat cancer.

The success of a classic inorganic coordination compound, Cisplatin, cis-[Pt(NH3)2Cl2], as the first anticancer metallodrug started a field of research dedicated to discovering coordination compounds with antitumor activity, encompassing various metals. Among these, copper complexes have emerged as interesting candidates to develop drugs to treat cancer. In this work, mixed ligand complexes of Cu(II) with diimines (phenanthroline or 4-methylphenanthroline) and 3-(4-hydroxyphenyl)propanoate, phenylcarboxylate or phenylacetate were synthesized. They were characterized in the solid state, including a new crystal structure of [Cu2(3-(4-hydroxyphenyl)propanoate)3(phenanthroline)2]Cl·H2O. The obtained complexes presented a variety of stoichiometries. In solution, complexes were partially dissociated in the corresponding Cu-diimine complex. The complexes bound to the DNA by partial intercalation and groove binding, as assessed by Circular Dichroism, relative viscosity change and UV-Vis titration. The cytotoxicity of the complexes was determined in vitro on MDA-MB-231, MCF-7 (human metastatic breast adenocarcinomas, the first triple negative), MCF-10A (breast nontumoral), A549 (human lung epithelial carcinoma), and MRC-5 (human nontumoral lung epithelial cells), finding an activity higher than that of Cisplatin, although with less selectivity.

Biological Evaluation of Dinuclear Platinum(II) Complexes with Aromatic N-Heterocycles as Bridging Ligands.

The history of effective anti-cancer medications begins with the discovery of cisplatin's anti-cancer properties. Second-generation analogue, carboplatin, with a similar range of effectiveness, made progress in improving these drugs with fewer side effects and better solubility. Renewed interest in platinum-based drugs has been increasing in the past several years. These developments highlight a revitalized enthusiasm and ongoing exploration in platinum chemotherapy based on the series of dinuclear platinum(II) complexes, [{Pt(L)Cl}2(µ-bridging ligand)]2+, which have been synthesized and evaluated for their biological activities. These complexes are designed to target various cancerous conditions, exhibiting promising antitumor, antiproliferative, and apoptosis-inducing activities. The current work aims to shed light on the potential of these complexes as next-generation platinum-based therapies, highlighting their enhanced efficacy and reduced side effects, which could revolutionize the approach to chemotherapy.

Structure and Functions of HMGB3 Protein.

HMGB3 protein belongs to the group of HMGB proteins from the superfamily of nuclear proteins with high electrophoretic mobility. HMGB proteins play an active part in almost all cellular processes associated with DNA-repair, replication, recombination, and transcription-and, additionally, can act as cytokines during infectious processes, inflammatory responses, and injuries. Although the structure and functions of HMGB1 and HMGB2 proteins have been intensively studied for decades, very little attention has been paid to HMGB3 until recently. In this review, we summarize the currently available data on the molecular structure, post-translational modifications, and biological functions of HMGB3, as well as the possible role of the ubiquitin-proteasome system-dependent HMGB3 degradation in tumor development.

Dynamic stem-loop extension by Pol θ and templated insertion during DNA repair.

Theta-mediated end joining (TMEJ) is critical for survival of cancer cells when other DNA double-stranded break repair pathways are impaired. Human DNA polymerase theta (Pol θ) can extend ssDNA oligonucleotides, but little is known about preferred substrates and mechanism. We show that Pol θ can extend both ssDNA and RNA substrates by unimolecular stem-loop synthesis initiated by only two 3' terminal base pairs. Given sufficient time, Pol θ uses alternative pairing configurations that greatly expand the repertoire of sequence outcomes. Further primer-template adjustments yield low-fidelity outcomes when the nucleotide pool is imbalanced. Unimolecular stem-loop synthesis competes with bimolecular end joining, even when a longer terminal microhomology for end joining is available. Both reactions are partially suppressed by the ssDNA-binding protein replication protein A. Protein-primer grasp residues that are specific to Pol θ are needed for rapid stem-loop synthesis. The ability to perform stem-loop synthesis from a minimally paired primer is rare among human DNA polymerases, but we show that human DNA polymerases Pol η and Pol λ can catalyze related reactions. Using purified human Pol θ, we reconstituted in vitro TMEJ incorporating an insertion arising from a stem-loop extension. These activities may help explain TMEJ repair events that include inverted repeat sequences.

The intrinsically disordered transactivation region of HOXA9 regulates its function by auto-inhibition of its DNA-binding activity.

HOXA9 transcription factor is expressed in hematopoietic stem cells and is involved in the regulation of their differentiation and maturation to various blood cells. HOXA9 is linked to various leukemia and is a marker for poor prognosis of acute myeloid leukemia (AML). This protein has a conserved DNA-binding homeodomain and a transactivation domain. We show that this N-terminal transactivation domain is intrinsically disordered and inhibits DNA-binding by the homeodomain. Using NMR spectroscopy and molecular dynamics simulation, we show that the hexapeptide 197AANWLH202 in the disordered region transiently occludes the DNA-binding interface. The hexapeptide also forms a rigid segment, as determined by NMR dynamics, in an otherwise flexible disordered region. Interestingly, this hexapeptide is known to mediate the interaction of HOXA9 and its TALE partner proteins, such as PBX1, and help in cooperative DNA binding. Mutation of tryptophan to alanine in the hexapeptide abrogates the DNA-binding auto-inhibition. We propose that the disordered transactivation region plays a dual role in the regulation of HOXA9 function. In the absence of TALE partners, it inhibits DNA binding, and in the presence of TALE partners it interacts with the TALE protein and facilitates the cooperative DNA binding by the HOX-TALE complex.

Synergistic effects and competitive relationships between DOC and DOX as acting on DNA molecules: Studied with confocal Raman spectroscopy and molecular docking technology.

Docetaxel (DOC) is one of the second-generation antineoplastic drugs of the taxanes family with excellent antitumor activity. However, the mechanism of DOC inducing tumor cell apoptosis and treating cancer diseases, especially its interaction with DNA in the nucleus, and its adjuvant or combined Doxorubicin (DOX) acting on DNA molecules are unclear. In this study, the interaction mechanism between DOC and DNA, as well as the synergistic effects and competitive relationships among DOC and DOX when they simultaneously interact with DNA molecules were studied by laser confocal Raman spectroscopy combined with UV-visible absorption spectroscopy and molecular docking technology. The spectroscopic results showed that the binding constant of DOC to DNA is 5.25 × 103 M-1, the binding modes of DOC and DNA are non-classical intercalation and electrostatic binding, and the DNA-DOC complex has good stability. When DOC or DOX interacts with DNA alone, both of them can bind with bases and phosphate backbone of DNA, and also lead to DNA conformation changes; when DOC and DOX interact with DNA at the same time, the orders of interaction not only affect their binding sites with DNA, but also cause changes in the surrounding environment of the binding sites. In addition, the molecular docking results further verified that DOC and DOX have synergy and competition when they interact with DNA molecules simultaneously. The docking energies of DNA-DOC and DNA-DOX indicate the important role of van der Waals forces and hydrogen bonds. This study has practical significance for the design and development of antitumor drugs with less toxic based on the taxanes family and the combination with other drugs for the treatment of cancer.

A real-time biochemical assay for quantitative analyses of APOBEC-catalyzed DNA deamination.

Over the past decade, the connection between APOBEC3 cytosine deaminases and cancer mutagenesis has become increasingly apparent. This growing awareness has created a need for biochemical tools that can be used to identify and characterize potential inhibitors of this enzyme family. In response to this challenge, we have developed a Real-time APOBEC3-mediated DNA Deamination assay. This assay offers a single-step set-up and real-time fluorescent read-out, and it is capable of providing insights into enzyme kinetics. The assay also offers a high-sensitivity and easily scalable method for identifying APOBEC3 inhibitors. This assay serves as a crucial addition to the existing APOBEC3 biochemical and cellular toolkit and possesses the versatility to be readily adapted into a high-throughput format for inhibitor discovery.

A real-time biochemical assay for quantitative analyses of APOBEC-catalyzed DNA deamination.

Over the past decade, the connection between APOBEC3 cytosine deaminases and cancer mutagenesis has become increasingly apparent. This growing awareness has created a need for biochemical tools that can be used to identify and characterize potential inhibitors of this enzyme family. In response to this challenge, we have developed a Real-time APOBEC3-mediated DNA Deamination (RADD) assay. This assay offers a single-step set-up and real-time fluorescent read-out, and it is capable of providing insights into enzyme kinetics and also offering a high-sensitivity and easily scalable method for identifying APOBEC3 inhibitors. This assay serves as a crucial addition to the existing APOBEC3 biochemical and cellular toolkit and possesses the versatility to be readily adapted into a high-throughput format for inhibitor discovery.

Cryo-EM Structure of AAV2 Rep68 bound to integration site AAVS1: Insights into the mechanism of DNA melting.

The Rep68 protein from Adeno-Associated Virus (AAV) is a multifunctional SF3 helicase that performs most of the DNA transactions required for the viral life cycle. During AAV DNA replication, Rep68 assembles at the origin and catalyzes the DNA melting and nicking reactions during the hairpin rolling replication process to complete the second-strand synthesis of the AAV genome. Here, we report the Cryo-EM structures of Rep68 bound to double-stranded DNA (dsDNA) containing the sequence of the AAVS1 integration site in different nucleotide-bound states. In the apo state, Rep68 forms a heptameric complex around DNA, with three Origin Binding Domains (OBDs) bound to the Rep Binding Site (RBS) sequence and three other OBDs forming transient dimers with them. The AAA+ domains form an open ring with no interactions between subunits and with DNA. We hypothesize the heptameric quaternary structure is necessary to load onto dsDNA. In the ATPγS-bound state, a subset of three subunits binds the nucleotide, undergoing a large conformational change, inducing the formation of intersubunit interactions interaction and interaction with three consecutive DNA phosphate groups. Moreover, the induced conformational change positions three phenylalanine residues to come in close contact with the DNA backbone, producing a distortion in the DNA. We propose that the phenylalanine residues can potentially act as a hydrophobic wedge in the DNA melting process.

5-Formylcytosine mediated DNA-peptide cross-link induces predominantly semi-targeted mutations in both Escherichia coli and human cells.

Histone proteins can become trapped on DNA in the presence of 5-formylcytosine (5fC) to form toxic DNA-protein conjugates. Their repair may involve proteolytic digestion resulting in DNA-peptide cross-links (DpCs). Here, we have investigated replication of a model DpC comprised of an 11-mer peptide (NH2-GGGKGLGK∗GGA) containing an oxy-lysine residue (K∗) conjugated to 5fC in DNA. Both CXG and CXT (where X = 5fC-DpC) sequence contexts were examined. Replication of both constructs gave low viability (<10%) in Escherichia coli, whereas TLS efficiency was high (72%) in HEK 293T cells. In E. coli, the DpC was bypassed largely error-free, inducing only 2 to 3% mutations, which increased to 4 to 5% with SOS. For both sequences, semi-targeted mutations were dominant, and for CXG, the predominant mutations were G→T and G→C at the 3'-base to the 5fC-DpC. In HEK 293T cells, 7 to 9% mutations occurred, and the dominant mutations were the semi-targeted G → T for CXG and T → G for CXT. These mutations were reduced drastically in cells deficient in hPol η, hPol ι or hPol ζ, suggesting a role of these TLS polymerases in mutagenic TLS. Steady-state kinetics studies using hPol η confirmed that this polymerase induces G → T and T → G transversions at the base immediately 3' to the DpC. This study reveals a unique replication pattern of 5fC-conjugated DpCs, which are bypassed largely error-free in both E. coli and human cells and induce mostly semi-targeted mutations at the 3' position to the lesion.

The Impact of Lens Epithelium-Derived Growth Factor p75 Dimerization on Its Tethering Function.

The transcriptional co-activator lens epithelium-derived growth factor/p75 (LEDGF/p75) plays an important role in the biology of the cell and in several human diseases, including MLL-rearranged acute leukemia, autoimmunity, and HIV-1 infection. In both health and disease, LEDGF/p75 functions as a chromatin tether that interacts with proteins such as MLL1 and HIV-1 integrase via its integrase-binding domain (IBD) and with chromatin through its N-terminal PWWP domain. Recently, dimerization of LEDGF/p75 was shown, mediated by a network of electrostatic contacts between amino acids from the IBD and the C-terminal α6-helix. Here, we investigated the functional impact of LEDGF/p75 variants on the dimerization using biochemical and cellular interaction assays. The data demonstrate that the C-terminal α6-helix folds back in cis on the IBD of monomeric LEDGF/p75. We discovered that the presence of DNA stimulates LEDGF/p75 dimerization. LEDGF/p75 dimerization enhances binding to MLL1 but not to HIV-1 integrase, a finding that was observed in vitro and validated in cell culture. Whereas HIV-1 replication was not dependent on LEDGF/p75 dimerization, colony formation of MLLr-dependent human leukemic THP-1 cells was. In conclusion, our data indicate that intricate changes in the quaternary structure of LEDGF/p75 modulate its tethering function.

Monomeric copper(II) complexes with unsymmetrical salen environment: Synthesis, characterization and study of biological activities.

Three new ONNO-donor tetradentate unsymmetrical salen ligands were synthesized by using o-phenyl diamine with substituted salicylaldehydes followed by a two-step reaction methodology. These three ligands by reaction with Cu(OAc)2.4H2O produced three new monomeric Cu(II) complexes, [CuII(L1-3)] (1-3). Elemental analysis, IR, UV-vis, NMR, and HR-ESI-MS techniques were used to analyze and characterize all the synthesized ligands and their corresponding metal complexes. Molecular structures of 1-3 were confirmed by the single-crystal-XRD analysis. Furthermore, the DNA binding ability of these complexes was checked through UV-vis, fluorescence spectroscopy, and also by circular dichroism studies. All the complexes were found to show an intercalation mode of binding with the Kb value in the range of 104-105 M-1. Finally, 1-3 was tested against two malignant (HeLa and A549) and non-cancerous (NIH-3T3) cell lines to check their in vitro antiproliferative activities. Among all, 1 is the most cytotoxic of the series having IC50 values of 5.7 ± 0.9 and 6.0 ± 0.3 µM against HeLa and A549 cell lines, respectively. This result is also consistent with the DNA binding order. Furthermore, the apoptotic mode of cell death of all the complexes was also evaluated by DAPI, AO/EB, and Annexin V-FITC/PI double staining assays.

Gold(III) complexes with thiosemicarbazone ligands: insights into their cytotoxic effects on lung cancer cells.

Cancer continues to pose a global threat, underscoring the urgent need for more effective and safer treatment options. Gold-based compounds have recently emerged as promising candidates due to their diverse range of biological activities. In this study, three gold(III) complexes derived from thiosemicarbazone ligands have been synthesized, fully characterized, including their X-ray crystal structures. We conducted initial mode-of-action studies on DNA and BSA, followed by a comprehensive investigation into the cytotoxic effects of these novel gold(III) complexes on lung cancer cells (A549, H2052, and H28). The results demonstrated a concentration-dependent cytotoxic response, with H28 cells exhibiting the highest sensitivity to the treatment. Furthermore, the analysis of the cell cycle revealed that these compounds induce cell cycle arrest and promote apoptosis as a response to treatment. We also observed distinct morphological changes and increased oxidative stress, contributing significantly to cell death. Notably, these complexes exhibited the ability to suppress interleukin-6 production in mesothelioma cell lines, and this highlights their anti-inflammatory potential. To gain an initial understanding of cytotoxicity on healthy cells, hemolysis tests were conducted against human blood cells, with no evidence of hemolysis. Furthermore, a toxicity assessment through the in vivo Galleria mellonella model underscored the absence of detectable toxicity. These findings prove that these complexes are promising novel therapeutic agents for lung cancer.

Synthesis, spectral characterisation, biocidal investigation, in-silico and molecular docking studies of 4-[(2-chloro-4-methylphenyl)carbamoyl]butanoic acid derived triorganotin(IV) compounds.

Three triorganotin(IV) compounds, R3Sn(L), with R = CH3 (1), n-C4H9 (2) and C6H5 (3), and LH = 4-[(2-chloro-4-methylphenyl)carbamoyl]butanoic acid, were prepared and confirmed by various techniques. A five-coordinate, distorted trigonal-bipyramidal geometry was elucidated for tin(IV) centres both in solution and solid states. An intercalation mode was confirmed for the compound SS-DNA interaction by UV-visible, viscometric techniques and molecular docking. MD simulation revealed stable binding of LH with SS-DNA. Anti-bacterial investigation revealed 2 to be generally the most potent, especially against Sa and Ab, i.e. having the lowest MIC values (≤0.25 µg/mL) compared to the standard anti-biotics vancomycin-HCl (MIC = 1 µg/mL) and colistin-sulphate (MIC = 0.25 µg/mL). Similarly, the anti-fungal profile shows 2 exhibits 100% inhibition against Ca and Cn fungal strains and has MIC values (≤0.25 µg/mL) comparatively lower than standard drug fluconazole (0.125 and 8 µg/mL for Ca and Cn, respectively). Compound 2 has the greatest activity with CC50 ≤ 25 µg/mL and HC50 > 32 µg/mL performed against HEC239 and RBC cell lines. The anti-cancer potential was assessed against the MG-U87 cell line, using cisplatin as the standard (133 µM), indicates 2 displays the greatest activity (IC50: 5.521 µM) at a 5 µM dose. The greatest anti-leishmanial potential was observed for 2 (87.75 at 1000 µg/mL) in comparison to amphotericin B (90.67). The biological assay correlates with the observed maximum of 89% scavenging activity exhibited by 2. The Swiss-ADME data publicised the screened compounds generally follow the rule of 5 of drug-likeness and have good bioavailability potential.

Spectroscopic and molecular modeling studies of binding interaction between the new complex of yttrium and 1,10-phenanthroline derivatives with DNA and BSA.

In this study, the 4,9 diazafluoren-9-one ligand and [Y(Daf)2Cl3.OH2] complex were synthesized. The interaction of this complex with DNA and bovine serum albumin (BSA) was investigated by UV-vis and fluorescence spectroscopy. The molecular docking method was used to confirm the experimental results, investigate the type of interaction, and determine the binding site. The binding constant and Stern-Volmer constant were calculated using spectroscopy techniques. The binding constant of the Y-complex with DNA and BSA obtained using the UV-vis technique was 1.61 × 105 M-1 and 0.49 × 105 M-1, while that obtained using the fluorescence method was 3.39 × 105 M-1 and 3.63 × 105 M-1, respectively. The results of experimental and theoretical data showed that the interaction between the yttrium complex and DNA and BSA is driven by the hydrogen bond and van der Waals interaction, respectively. The yttrium complex communicates with DNA via the groove interaction. This complex has high binding energy with bovine serum albumin. In addition, the molecular docking results showed that the complex binds to the IIA subdomain of BSA (site I). Finally, anticancer activity of the yttrium complex was studied on MCF-7 and A549 cell lines by using the MTT method. The IC50 values obtained showed that the yttrium complex possesses anticancer activity.

Studying the Interaction between Bendamustine and DNA Molecule with SERS Based on AuNPs/ZnCl2/NpAA Solid-State Substrate.

Bendamustine (BENDA) is a bifunctional alkylating agent with alkylating and purinergic antitumor activity, which exerts its anticancer effects by direct binding to DNA, but the detailed mechanism of BENDA-DNA interaction is poorly understood. In this paper, the interaction properties of the anticancer drug BENDA with calf thymus DNA (ctDNA) were systematically investigated based on surface-enhanced Raman spectroscopy (SERS) technique mainly using a novel homemade AuNPs/ZnCl2/NpAA (NpAA: nano porous anodic alumina) solid-state substrate and combined with ultraviolet-visible spectroscopy and molecular docking simulation to reveal the mechanism of their interactions. We experimentally compared and studied the SERS spectra of ctDNA, BENDA, and BENDA-ctDNA complexes with different molar concentrations (1:1, 2:1, 3:1), and summarized their important characteristic peak positions, their peak position differences, and hyperchromic/hypochromic effects. The results showed that the binding modes include covalent binding and hydrogen bonding, and the binding site of BENDA to DNA molecules is mainly the N7 atom of G base. The results of this study help to understand and elucidate the mechanism of BENDA at the single-molecule level, and provide guidance for the further development of effective new drugs with low toxicity and side effects.

Analytical studies on some pesticides with antifungal effects: Simultaneous determination by HPLC, investigation of interactions with DNA and DNA damages.

A simple, and fast method was developed for the simultaneous determination of five fungicides, namely thiram (THR), epoxiconazole (EPO), hexaconazole (HEX), tebuconazole (TEB), and diethofencarb (DIE), in different matrices by HPLC-UV. Parameters influencing the peak shape and resolution, such as the composition of mobile phase, pH and concentration of buffer solution, and column temperature, were examined and optimized. The proposed method was validated in terms of linearity, sensitivity, precision, and accuracy. Forced degradation studies were carried out for all analytes to demonstrate the specificity of the method and to evaluate the stability of analytes under different conditions. DNA interaction and DNA damage studies were conducted by HPLC and comet assay, respectively. All fungicides were found to bind DNA, except for DIE. While the binding coefficients for EPO, HEX, and TEB were of the order of 104, THR was found to interact more strongly with DNA with a binding coefficient of higher than 106. DIE did not induce DNA damage at any concentration tested. On the other hand, TEB, HEX, and EPO induced DNA damage up to 30 µg/mL. THR showed cytotoxic effects at 20 and 30 µg/mL and caused significant DNA damage at lower concentrations.

Synthesis, crystal structure, cytotoxicity, in-detail experimental and computational CT-DNA interaction studies of 2-picolinate Pd(II) and Pt(II) complexes.

A new Pd(II) complex of formula [Pd(en)(2-pyc)]+ (where, en is ethylenediamine and 2-pyc is 2-pyridinecarboxylate anion) and its reported Pt(II) analogue, i.e. [Pt(en)(2-pyc)]+ have been made by an improved synthetic procedure, yielding above 80%. They have been characterized by FT-IR, UV-Vis, 1H NMR, 13C NMR, conductivity and elemental analysis. Single crystal structural determination of [Pt(en)(2-pyc)]+ displayed that the Pt(II) cation in this complex coordinated by 2-pyc and en each as five member chelate resulting in slightly distorted square-planar array. The time-dependent spectroscopic analysis of these compounds in aqueous medium demonstrated their structural stabilities. The cytotoxic activities of Pd(II) and Pt(II) complexes, free 2-pyc and carboplatin (as standard drug) were assayed in-vitro against the HCT-116 and MCF-7 as cancerous and MCF 10 A and CCD-841 as normal cell lines. They showed the IC50 order of: carboplatin > 2-pyc > Pt(II) > Pd(II) and lower activities against non-cancerous cells. CT-DNA binding of the Pd(II), Pt(II) and 2-pyc free ligand were explored individually. In this relation, UV-Vis and fluorescence titrations disclosed quenching of CT-DNA absorption and emissions by the compounds via dynamic mechanism and formation of H-bonds and van der Waals forces between them. The interaction was further validated and verified by viscosity measurements and gel electrophoresis. Partition coefficient determination showed that all three compounds have more lipophilicity than cisplatin. Furthermore, docking analysis and molecular dynamics simulation were done to evaluate the nature of interaction between aforementioned compounds and CT-DNA. The finding results demonstrated that these agents interact with CT-DNA via groove binding and were in agreement with experimental results.Communicated by Ramaswamy H. Sarma.