DNA interaction, docking, molecular modelling and biological studies of o-Vanillin derived Schiff base metal complexes

DNA interaction studies of a cobalt(III) complex containing β-amino alcohol ligand by spectroscopic and molecular docking methods

In the present research, the feasibility of a Cobalt(III) complex containing β-amino alcohol ligands for affinity with the target calf thymus DNA is demonstrated. In the title complex, [Co(C11H15N2O2)2]Cl, the Co(III) atom is six-coordinated with four N atoms and two O atoms from (2-[(E)-({2-[(2-Hydroxyethyl) amino]ethyl}imino)methyl]phenol) ligand (L). To investigate the molecular interaction between the synthesized complex and DNA, some multi-spectroscopic approaches associated with molecular docking were employed in the physiological buffer (pH 7.4). The results indicated that the Co(III) complex proved to be a minor groove binder with a preference for the A-T region, which was substantiated by displacement studies with Hoechst33258 and Methylene blue (MB) as minor groove binder and intercalator. In addition, the results of the molecular docking study revealed that the Co(III) complex approached the gap between the DNA minor grooves near the spot where the Hoechst was. Furthermore, the results of the cytotoxicity and apoptosis tests for the MCF-7 cell line were also indicative of the positive effects of the complex on controlling the growth and viability of breast cancer.Communicated by Ramaswamy H. Sarma.

Correlating the charge transfer efficiency of metallic sulfa-isatins to design efficient NLO materials with better drug designs

The present study presents synthesis, characterization and first principle studies on metal chelates, (1-12), of sulfonamide-isatin reacted ligands (S¹-S³). All the products were evaluated by various physical and spectral (UV, IR, NMR, MS) means. The octahedral geometry for Co⁺², Ni⁺² and Zn⁺², while square planner geometry for Cu⁺² chelates were confirmed by their spectroscopic and magnetic data. Their physical chemistry investigation show the ability of aromatic rings to stabilize sulfonamide rings across NH-π interactions at their optimized geometries. The nonlinear optical response for all the compounds disclosed that the z-axis has the most contributions. An efficient electron injection and hole studies for Au and Al electrodes having the energies of - 0.1-3.1 and 0.0-11.8 eV respectively were noted. Their bioactive character was shown by global reactivity calculated from FMO energy gaps. The enzyme inhibitory results were found to be 45-61% and IC₅₀ = 102-122 µL, for compound (4), (10), (8), (5) and (12) against the amylase, protease, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) respectively The antibacterial findings showed significant action having 11-17 mm for (2), (7) and (10) for bacterial species, Escherichia coli and Micrococcus luteus. The DPPH and ferric reducing power assay was used to evaluate the antioxidant capacity with 49.0 ± 0.09-66.2 ± 0.08% and IC₅₀ = 102.3-122.4 µL range. In comparison to ligands, the results showed that all metal chelates had higher bioactivity. The chelation was the primary cause of their increased bioactivity. These findings suggested that such metal-based compounds might be used as antimicrobial, and antioxidant options in future to cope drug resistance.

Metformin-Derived Water-Soluble Cobalt Complexes: Thermal, Spectroscopic, DNA Interaction, and Molecular Docking Studies

Novel three water-soluble cobalt (II) complexes of type [Co(metf)(o-phen)₂]Cl₂ (1), [Co(metf)(opda)₂]Cl₂ (2), and [Co(metf)(2-2'bipy)₂]Cl₂ (3) (Metf, metformin; o-phen, ortho-phenanthroline; opda, ortho-phenylenediamine; 2,2'-bipy, 2,2'-bipyridine) were synthesized and characterized by various analytical and spectral techniques. Based on these studies, octahedral geometry is assigned to these complexes. The stability of the complexes has been calculated from quantum chemical parameters using HOMO-LUMO energies. Thermal degradation pattern of the compounds was studied and Coats-Redfern method is used to determine kinetic parameters for complexes 1, 2, and 3 from thermal studies. The DNA interaction of these complexes was investigated by absorption, emission, and viscosity studies. From the spectral data, it was concluded that the complexes bind to DNA through groove mode of binding. The intrinsic binding constants (K_b) from absorption spectroscopy were 2.49 × 10⁴, 2.48 × 10⁴, and 2.64 × 10⁴ M^-1 for 1, 2, and 3, respectively, and Stern-Volmer quenching constants (K_sv) from emission spectroscopy were 0.21, 0.20, and 0.13, respectively. These complexes were screened for nuclease activity of pUC19 DNA, in the presence of H₂O₂. Discovery studio 2.1 software was used to evaluate binding affinity and interaction pattern of complexes with B-DNA receptor protein and the maximum dock score is seen for complex 2.

Metal Complexes as DNA Synthesis and/or Repair Inhibitors: Anticancer and Antimicrobial Agents

Medicinal inorganic chemistry involving the utilization of metal-based compounds as therapeutics has become a field showing distinct promise. DNA and RNA are ideal drug targets for therapeutic intervention in the case of various diseases, such as cancer and microbial infection. Metals play a vital role in medicine, with at least 10 metals known to be essential for human life and a further 46 nonessential metals having been involved in drug therapies and diagnosis. These metal-based complexes interact with DNA in various ways, and are often delivered as prodrugs which undergo activation in vivo. Metal complexes cause DNA crosslinking, leading to the inhibition of DNA synthesis and repair. In this review, the various interactions of metal complexes with DNA nucleic acids, as well as the underlying mechanism of action, were highlighted. Furthermore, we also discussed various tools used to investigate the interaction between metal complexes and the DNA. The tools included in vitro techniques such as spectroscopy and electrophoresis, and in silico studies such as protein docking and density-functional theory that are highlighted for preclinical development.

Synthesis, characterization, ADMET, in vitro and in vivo studies of mixed ligand metal complexes from a curcumin Schiff base and lawsone

Complexes are currently synthesized from plant origin because of their therapeutic effect against certain diseases with toxicity. Hence, in this work, four new transition metal(II) mixed ligand complexes have been synthesized using a curcumin Schiff base (primary ligand) and lawsone (as co-ligand). The geometry of these complexes was explored by elemental analyses, molar conductance, thermal analysis, magnetic moment values, IR, NMR, Mass, electronic and EPR spectral studies. Electronic absorption titrations, viscosity measurements and molecular docking studies reveal that all the metal complexes interact with the CT DNA by groove binding. Among all the complexes, the copper(II) complex (complex 1) exhibits a higher K_b value (3.5 × 10^-4 M) which reveals that it has a strong binding efficiency toward the CT DNA. The complexes also possess strong DNA cleavage efficiency. Cytotoxicity investigations on Artemia salina show that all the complexes possess higher cytotoxic effect than the ligand. Moreover, all the metal complexes have better antimicrobial efficacy than the ligand. Swiss ADME, PASS and pkCSM online softwares are helpful to predict the pharmacokinetic and biological actions of the curcumin Schiff base. Theoretical results obtained from the in silico study are experimentally corroborated by in vivo anti-inflammatory screening study. All the above studies demonstrate that the copper complex possesses biological activity similar to that of the drug like molecules. Research Highlights Synthesis and characterization of four novel transition mixed ligand complexes using plant moieties Promising in vivo anti-inflammatory agents and in vitro DNA metallonucleases Cytotoxicity investigation on Artemia salina Higher cytotoxic effect for the complexes than the ligand Identification of copper(II) complex as lead like molecule among all.

The study on the interactions of two 1,2,3-triazoles with several biological macromolecules by multiple spectroscopic methodologies and molecular docking

1-(4-chlorophenyl)-5-phenyl-1H-1,2,3-triazole (CPTC) and 5-(3-chlorophenyl) -1-phenyl-1H-1,2,3-triazole (PCTA) are two new derivatives of 1,2,3-triazole. Their structural and spectral properties were characterized by density functional theory calculations (DFT). The binding properties of CPTC or PCTA with several typical biomacromolecules such as human serum albumin (HSA), bovine hemoglobin (BHb), human immunoglobulin (HIgG) or DNA were investigated by molecular docking and multiple spectroscopic methodologies. The different parameters including binding constants and thermodynamic parameters for CPTC/PCTA-HSA/BHb/HIgG/DNA systems were obtained based on various fluorescence enhancement or quenching mechanisms. The results of binding constants indicated that there were the strong interactions between two triazoles and four biological macromolecules due to the higher order of magnitude between 10³ and 10⁵. The values of thermodynamic parameters revealed that the binding forces for these systems are mainly hydrophobic interactions, electrostatic force, or hydrogen bond, respectively, which are in agreement with the results of molecular docking to a certain extent. Moreover, the information from synchronous, 3D fluorescence and UV-Vis spectroscopies proved that two compounds CPTC and PCTA could affect the microenvironment of amino acids residues of three kinds of proteins. Based on the above experimental results, a comparison of the interaction mechanisms for CPTC/PCTA-proteins/DNA systems have been performed in view of their different molecular structures, which is beneficial for the further research in order to design them as the novel drugs.