Synthesis, DNA binding and complex formation reactions of 3-amino-5,6-dimethyl-1,2,4-triazine with Pd(II) and some selected biorelevant ligands

Investigation on CT-DNA and Protein Interaction of New Pd(II) Complexes Involving Ceftazidime and 3-Amino-1,2,3-triazole: Synthesis, Characterization, Biological Impact, Anticancer Evaluation, and Molecular Docking Approaches

Two new palladium (II) complexes, [Pd(CAZ)(OH2 )2 ]2+ (1) and [Pd(3-AT)(OH2 )2 ]2+ (2), (CAZ=ceftazidime, and 3-AT=amitrole) were synthesized and studied for their potential as anticancer drugs with low toxicity and high potency. To fully characterize these complexes, we conducted elemental analysis and FT-IR studies. Furthermore, we irradiated the complexes with Indian 60 Co gamma rays and thoroughly evaluated their antimicrobial properties. Our results demonstrate that the inhibitory activity of complexes was significantly enhanced against (G+) bacteria and fungi. Additionally, we probed the complexes' interaction with CT-DNA and BSA using various techniques, including UV-vis spectroscopy, thermal denaturation, viscometry, gel electrophoresis, and molecular docking studies. Our findings conclusively demonstrate that these complexes possess a strong binding interaction with CT-DNA via minor groove binding and/or electrostatic interactions, as well as excellent binding affinity to BSA. Finally, we conducted a cytotoxicity assay that clearly indicates these complexes hold immense promise as cell growth inhibitors against MCF-7 and HCT-116.

Antimicrobial screening involving Helicobacter pylori of nano-therapeutic compounds based on the amoxicillin antibiotic drug

Nano-structure Cu(II) complex [Cu(AMAB)2 ]Cl2 with Schiff base (AMAB) derived from the condensation between 4-(dimethylamino)benzaldehyde and amoxicillin trihydrate was prepared. (AMAB) Schiff base and its Cu(II) complex were identified and confirmed by different physicochemical techniques. The Schiff base (AMAB) was coordinated to copper ion through carbonyl oxygen and imine nitrogen donor sites. X-ray powder diffraction shows a cubic crystal system of the Cu(II) complex. The density functional theory was used to optimize the structure geometries of the investigated compounds. The molecular docking of the active amino acids of the investigated proteins' interactions with the tested compounds was evaluated. The bactericidal or bacteriostatic effect of the compounds was screened against some bacterial strains. The activity of Cu-chelate against Gram-negative bacteria was mainly more effective than its (AMAB) ligand and vice versa in the case of Gram-positive bacteria. The biological activity of the prepared compounds with biomolecules calf thymus DNA (CT-DNA) was determined by electronic absorption spectra and DNA gel electrophoresis technique. All studies revealed that the Cu-chelate derivative exhibited better binding affinity to both CT-DNA than the AMAB and amoxicillin itself. The anti-inflammatory effect of the designed compounds was determined by testing their protein denaturation inhibitory activity spectrophotometrically. All obtained data supported that the designed nano-Cu(II) complex with Schiff base (AMAB) is a potent bactericide against H. pylori, and exhibits anti-inflammatory activity. The dual inhibition effects of the designed compound represent a modern therapeutic approach with extended spectrum of action. Therefore, it can act as good drug target in antimicrobial and anti-inflammtory therapies. Finally, H. pylori resistance to amoxicillin is absent or rare in many countries, thus amoxicillin nanoparticles may be beneficial for countries where amoxicillin resistance is reported.

Decrypting the interaction pattern of Piperlongumine with calf thymus DNA and dodecamer d(CGCGAATTCGCG)2 B-DNA: Biophysical and molecular docking analysis

The mechanisms of interaction of DNA with pharmacological molecules are critical to understanding their therapeutic actions on physiological systems. Piperlongumine is widely studied for its anticancer potential. Multi-spectrometry, calorimetry and in silico studies were employed to study the interaction of piperlongumine and calf thymus DNA. UV-Vis spectroscopy illustrated a hyperchromic pattern in spectra of the calf thymus DNA-piperlongumine complex, while fluorescent quenching was observed in emission spectral studies. Competitive displacement assay demonstrated higher displacement and binding constant for DNA-rhodamine B complex by piperlongumine than DNA-methylene blue complex. Differential scanning calorimetry presented non-significant changes in melting temperature and molecular docking presented the precise interaction site of piperlongumine with calf thymus DNA at minor groove. Further, piperlongumine treatment did not result in pBluescript KS plasmid DNA cleavage as revealed from the DNA topology assay. All these experiments confirmed the binding of piperlongumine with DNA through minor groove binding mode.

Multi-stage screening to predict the specific anticancer activity of Ni(II) mixed-ligand complex on gastric cancer cells; biological activity, FTIR spectrum, DNA binding behavior and simulation studies

The anticancer activity of a transition metal complex with [Ni(L¹)₂L²]H₂O (where L¹ and L² were acetylacetonato (acac) and 2-aminopyridine (2-ampy), respectively) was evaluated in MKN45 cell line. Methyl thiazolyl tetrazolium (MTT) assay was performed to assess the antitumor capacity of the Ni(II) complex against gastric cancer cell line MKN45. The complexexhibited high in vitro antitumor activity against MKN45 cells with IC₅₀values of 1.99 μM in 48 hrs. The alterations in the structure of cellular biomolecules (proteins, lipids, carbohydrates, and especially DNA) by the Ni(II) complex were confirmed by bio spectroscopic studies. Fourier Transformed Infrared (FTIR) spectroscopy analysis revealed significant differences between untreated and treated MKN45 cell line in the region of glycogen, nucleic acid, amide I and amide II bands (1000, 1100, ~1650, and ~1577 cm^-1). The absorption bands 1150 cm^-1 and 1020-1025 cm^-1 can be assigned to the CO bond of glycogen and other carbohydrates and are significantly overlapped by DNA. The interaction of calf thymus (CT) DNA with Ni(II) complex was explored using absorption spectral method. The UV-visible studies demonstrated that this complex was able to bind with DNA via groove, non-covalent, and electrostatic interactions, and binding constant (K_b) was found to be 3 * 10⁴. Docking simulation and Non Covalent Interaction (NCI) topological analysis were conducted to provide insights into the nature of DNA/complex interactions. The binding affinity and binding stability of complex was validated by 400-ns MD simulations.

Luminescent anticancer Ru(II)-arenebipyridine and phenanthroline complexes: Synthesis, characterization, DFT studies, biological interactions and cellular imaging application

A series of ruthenium(II)-arene complexes of several bipyridine and phenanthroline derivatives have been synthesized by employing a green and efficient protocol involving water as a solvent under sonication. The structures of all the complexes were elucidated by the spectroscopic analysis. The geometry of the chlorido and PTA (1,3,5-Triaza-7-phosphaadamantane) complexes were further confirmed by DFT and single crystal XRD. The stability study in various solvents, specifically in the intracellular one was conducted. Most of the compounds exhibited significant potency and selectivity against MCF7 and HeLa cell lines with respect to normal HEK-293 cells compared to cisplatin and RAPTA-C (Ruthenium(II)-arene PTA complex). Complex [(η6-hexamethylbenzene)RuCl(κ2-N,N-4,4'-di-n-nonyl-2,2'-bpy)]Cl (3e) presented best anticancer profiles against all the human cancer cells. Interestingly, few complexes turned up to be highly fluorescent depicted by the quantum yield values. Remarkably, [(η6-p-cymene)RuCl(κ2-N,N-bpy)]Cl (3i) was identified as most significant anticancer theranostic agent interms of potency, selectivity and fluorescence quantum yield. This complex also represented itself as significant cellular imaging agent in live U-87 MG cells which was monitored by confocal microscope. Absorption and emission spectral studies of bypyridine and phenanthroline complex series revealed that the complexes interacted with calf thymus DNA through groove binding as well as intercalative mode. In addition to this, strong binding efficacy of these scaffolds wih BSA (Bovin Serum Albumin) also enhanced their transportation property inside the cells.

Synthesis, characterization and biological application of four novel metal-Schiff base complexes derived from allylamine and their interactions with human serum albumin: Experimental, molecular docking and ONIOM computational study

Novel metal-based drug candidate including VOL2, NiL2, CuL2 and PdL2 have been synthesized from 2-hydroxy-1-allyliminomethyl-naphthalen ligand and have been characterized by means of elemental analysis (CHN), FT-IR and UV-vis spectroscopies. In addition, (1)H and (13)C NMR techniques were employed for characterization of the PdL2 complex. Single-crystal X-ray diffraction technique was utilized to characterise the structure of the complexes. The Cu(II), Ni(II) and Pd(II) complexes show a square planar trans-coordination geometry, while in the VOL2, the vanadium center has a distorted tetragonal pyramidal N2O3 coordination sphere. The HSA-binding was also determined, using fluorescence quenching, UV-vis spectroscopy, and circular dichroism (CD) titration method. The obtained results revealed that the HSA affinity for binding the synthesized compounds follows as PdL2>CuL2>VOL2>NiL2, indicating the effect of metal ion on binding constant. The distance between these compounds and HSA was obtained based on the Förster's theory of non-radiative energy transfer. Furthermore, computational methods including molecular docking and our Own N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM) were carried out to investigate the HSA-binding of the compounds. Molecular docking calculation indicated the existence of hydrogen bond between amino acid residues of HSA and all synthesized compounds. The formation of the hydrogen bond in the HSA-compound systems leads to their stabilization. The ONIOM method was utilized in order to investigate HSA binding of compounds more precisely in which molecular mechanics method (UFF) and semi empirical method (PM6) were selected for the low layer and the high layer, respectively. The results show that the structural parameters of the compounds changed along with binding to HSA, indicating the strong interaction between the compounds and HSA. The value of binding constant depends on the extent of the resultant changes. This should be mentioned that both theoretical methods calculated the Kb values in the same sequence and are in a good agreement with the experimental data.