DNA and HSA interaction of Vanadium (IV), Copper (II), and Zinc (II) complexes derived from an asymmetric bidentate Schiff-base ligand: multi spectroscopic, viscosity measurements, molecular docking, and ONIOM studies

Two new complexes, [Ho(L) 2 NO 3 ] n (1) and [Co(L′) 2 Cl 4 ] n (2) (HL = 3,5bis(triazol-1-yl)benzoic acid, HL′ = 2,4-bis(triazol-1-yl)benzoic acid), have been synthesized and characterized. Interactions with DNA through absorption titration experiments, fluorescence spectra, viscosity measurements and a molecular docking study were examined. The results suggested that complexes 1 and 2 interact with DNA in a partial intercalation mode. DNA binding affinity was determined using k b values, which indicated that the binding activity of the complexes to DNA was complex 2 (k b = 1.93 × 10 4 ) > complex 1 (k b = 1.06 × 10 4 ). Gel electrophoresis assay demonstrated that the complexes have the ability to cleave pBR322 DNA. Apoptotic assay indicated that the complexes can induce programmed death of Hela cells (human cervix carcinoma cells). A cytotoxicity study indicated that complex 2 shows a greater inhibitory rate of Hela cells than complex 1 and the cytotoxicity of both 1 and 2 showed time dependence. Especially, the efficacy of complex 2 was shown to be higher than that of cisplatin at 72 h.

Section: Resultssupporting

confidence: 83%

Two Ho(III) and Co(II) complexes constructed from bis(triazol‐1‐yl)benzoic acid with structurally similar carboxyl ligands: Syntheses, structures and biological activities

Zhu

Wang

Meng

et al. 2018

“…The IR spectrum of the ligand showed a broad band of (OH) stretching at 3432 cm −1 that corresponded to the phenolic band. [21,22] The azo group (-N=N-) appeared at 1661 cm −1 . [23] This indicated that the ligand preparation was done in good form.…”

Section: Characterization Of Azo-dye Ligand (H 2 L)mentioning

confidence: 99%

Metal complexes of tetradentate azo‐dye ligand derived from 4,4′‐oxydianiline: Preparation, structural investigation, biological evaluation and MOE studies

Deghadi

Mahmoud

Mohamed

2020

The Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II) and Cd (II) complexes were prepared by reaction of its metal chlorides with new azo‐dye ligand (H2L). The ligand derived from 4,4′‐oxydianiline and 2‐amino‐4‐chlorophenol was synthesized in a 1:2 molar ratio. The structure of the ligand and its metal complexes was investigated using different tools such as elemental analysis (C, H, N and M), molar conductivity, IR, UV–vis, 1H‐NMR, mass spectrometry and thermogravimetric and differential thermogravimetric studies. The data showed that the ligand acted as a N,N,O,O‐binegative tetradentate ligand. All metal complexes had a octahedral structure as depicted by spectral and elemental analyses. The conductivity data showed the electrolytic nature of the Cr (III) and Fe (III) complexes while the other complexes were nonelectrolytes. Thermal analysis studies showed the decomposition of the complexes in four to five steps with the weight loss of hydrated water in the first decomposition step followed by the coordinated water and ligand molecules. Biological activity was tested for the prepared compounds against four bacterial species (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and against two fungal species (Aspergillus fumigatus and Candida albicans). Also, all complexes were screened for anticancer activities against a breast cancer (MCF‐7) cell line. The [Co(L)(H2O)2] complex showed the lowest IC50 value. Molecular docking is a key tool in computer drug design. Therefore, investigation of protein receptors and ligand interaction plays a vital role in the design of structurally based drugs. As a result, docking studies were investigated for H2L ligand, [Mn(L)(H2O)2] and [Ni(L)(H2O)2] complexes with 5KBC, 3V7B and 4G9M receptors.

“…EtBr is a conjugate planar molecule used as a spectral probe. Its fluorescence intensity is very weak, but it is greatly increased when EtBr is specifically intercalated into the base pairs of double‐stranded . Binding of the complexes to DNA decreases the emission intensity, and the extent of the reduction of the emission intensity gives a measure of the DNA‐binding propensity of the complexes and stacking interaction between the adjacent DNA base pairs .…”

Section: Resultsmentioning

confidence: 99%

“…Its fluorescence intensity is very weak, but it is greatly increased when EtBr is specifically intercalated into the base pairs of double‐stranded . Binding of the complexes to DNA decreases the emission intensity, and the extent of the reduction of the emission intensity gives a measure of the DNA‐binding propensity of the complexes and stacking interaction between the adjacent DNA base pairs . According to the classical Stern–Volmer equation: I/I 0 = 1 + K sq r , where I represents the fluorescence intensity in the absence of the complex and I 0 represents the fluorescence intensity in the presence of the complex, and r is the concentration ratio of complex to DNA, K sq is a linear Stern–Volmer quenching constant, depending on the ratio of binding concentration of EtBr to DNA concentration.…”

Section: Resultsmentioning

confidence: 99%

Structure and cytotoxicity of zinc (II) and cobalt (II) complexes based on 1,3,5‐tris(1‐imidazolyl) benzene

Zhu

Zhao

Peng

et al. 2019

Three novel complexes, [Zn (tib)2·(H2O)2]·(NO3)2 (1), [Co (tib)2]·2NO3 (2) and [Co2(tib)2(btc)]·H2O (3) [H4btc = 1,2,4,5‐benzenetetracarboxylic acid; H2tib = 1,3,5‐tris(1‐imidazolyl)benzene], were synthesized and characterized by single‐crystal X‐ray, IR and elemental analysis. The interaction of these complexes with FS‐DNA (fish sperm DNA) was monitored, and binding constants were determined using UV/Vis, which revealed that they have the ability to bind to FS‐DNA. DNA‐binding constants (K) for the three complexes were 2.2 × 104 m−1, 0.7 × 104 m−1 and 0.09 × 104 m−1, respectively. The interaction capacity of the complexes with FS‐DNA has been investigated by fluorescence spectroscopy. Stern–Volmer quenching plot values for complexes 1, 2 and 3 were 0.3784, 0.1028 and 0.076, respectively. The viscosity measurement suggested that complexes 1, 2 and 3 interact with DNA in an intercalation mode. In addition, anti‐cancer activities of these complexes investigated through MTT assays in vitro indicated that the complexes showed good cytotoxic activity against cancer cell lines. Cytotoxic activity of test complexes against two different cancer cell lines (HeLa and KB cells) showed significant cancer cell inhibition rates. Flow cytometry experiments and morphological apoptosis studies showed that the complexes induced apoptosis of HeLa tumor cell lines. Finally, a further molecular docking technique was employed to confirm the binding of the complexes toward the molecular target DNA.