Synthesis, spectral characterization, antimicrobial evaluation studies and cytotoxic activity of some transition metal complexes with tridentate (N,N,O) donor azo dye ligand

Synthesis, DFT Calculations, and Biological Studies of New 2-Cyano-3-(Naphthalene-1-yl) Acryloyl Amide Analogues as Anticancer Agents

A set of novel naphthalene derivatives was synthesized via investment of the electrophilic reaction center of the easily obtainable starting substance, 2-cyano-3-(naphthalen-1-yl)acryloyl chloride (1), with various nitrogen nucleophiles and assessed as potential antitumor agents. The chemical structures of these derivatives were completely specified using several spectral and elemental analyses. The antiproliferative efficacy of the discovered compounds against the human cancer cell lines HepG2 and MCF-7 was investigated. Compounds 12b and 9 have more potent anticancer activity versus MCF-7 breast cancer. DFT calculations for the synthesized compounds were studied to determine molecular geometry, frontier orbital analysis, and molecular electrostatic potential. Compound 2 has the lowest energy gap, the highest softness, and the lowest hardness molecule. Also, the electrophilicity values of the studied molecules provide evidence for their biological effectiveness, as compound 9 had significant antiproliferative activity and a high value of electrophilicity (ω) (0.190 eV).

Synthesis, characterization, and antibacterial activity studies of two Co(II) complexes with 2-[(E)-(3-acetyl-4-hydroxyphenyl)diazenyl]-4-(2-hydroxyphenyl)thiophene-3-carboxylic acid as a ligand

Two new Cobalt(II) complexes 12 and 13 have been synthesized from 2-[(E)-(3-acetyl-4-hydroxyphenyl)diazenyl]-4-(2-hydroxyphenyl)thiophene-3-carboxylic acid (11) as a novel ligand. These three new compounds were characterized on the basis of their powder X-Ray Diffraction, UV-Vis, IR, NMR, elemental analysis and MS spectral data. DFT/B3LYP mode of calculations were carried out to determine some theorical parameters of the molecular structure of the ligand. The purity of the azoic ligand and the metal complexes were ascertained by TLC and melting points. The analysis of the IR spectra of the polyfunctionalized azo compound 11 and its metal complexes 12 and 13, reveals that the coordination patterns of the ligand are hexadentate and tetradentate respectively. Based on the UV-Vis electronic spectral data and relevant literature reports, the ligand and derived complexes were assigned the E (trans) isomer form. Likewise, octahedral and square-planar geometries were respectively assigned to the cobalt(II) complexes. The broth microdilution method was used for antibacterial assays through the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The ligand 11 displayed moderate antibacterial activity (MIC = 32-128 μg/mL) against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa and Klebsiella pneumoniae 22. The octahedral cobalt(II) complex 12 showed moderate activity against Pseudomonas aeruginosa (MIC = 128 μg/mL) and Klebsiella pneumoniae 22 (MIC = 64 μg/mL) and none against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922, whereas the square-planar complex 13 displayed moderate activity only on Klebsiella pneumoniae 22 (MIC = 64 μg/mL).

Unsymmetrical Pd(II) Pincer Complexes with Benzothiazole and Thiocarbamate Flanking Units: Expedient Solvent-Free Synthesis and Anticancer Potential

Driven by the growing threat of cancer, many research efforts are directed at developing new chemotherapeutic agents, where the central role is played by transition metal complexes. The proper ligand design serves as a key factor to unlock the anticancer potential of a particular metal center. Following a recent trend, we have prepared unsymmetrical pincer ligands that combine benzothiazole and thiocarbamate donor groups. These compounds are shown to readily undergo direct cyclopalladation, affording the target S,C,N-type Pd(II) pincer complexes both in solution and in the absence of a solvent. The solid-phase strategy provided the complexes in an efficient and ecologically friendly manner. The resulting palladacycles are fully characterized using nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy and, in one case, by single-crystal X-ray diffraction (XRD). The solvent-free reactions are additionally analyzed by powder XRD. The pincer complexes exhibit remarkable cytotoxicity against several solid and blood cancer cell lines, including human colorectal carcinoma (HCT116), breast cancer (MCF7), prostate adenocarcinoma (PC3), chronic myelogenous leukemia (K562), multiple plasmacytoma (AMO1), and acute lymphoblastic leukemia (H9), with the dimethylamino-substituted derivative being particularly effective. The latter also induced an appreciable level of apoptosis in both parental and doxorubicin-resistant cells K562 and K562/iS9, vindicating the high anticancer potential of this type of palladacycles.

Antitumor and Antibacterial Activity of Ni(II), Cu(II), Ag(I), and Hg(II) Complexes with Ligand Derived from Thiosemicarbazones: Characterization and Theoretical Studies

Four new complexes (Ni2+, Cu2+, Ag+, and Hg2+) were prepared from the ligand N-(4-chlorophenyl)-2-(phenylglycyl)hydrazine-1-carbothioamide (H2L). Analytical and spectroscopic techniques were used to clarify the structural composition of the new chelates. In addition, all chelates were tested against bacterial strains and the HepG2 cell line to determine their antiseptic and carcinogenic properties. The Ni(II) complex was preferable to the other chelates. Molecular optimization revealed that H2L had the highest reactivity, followed by Hg-chelate, Ag-chelate, Ni-chelate, and Cu-chelate. Moreover, molecular docking was investigated against two different proteins: the ribosyltransferase enzyme (code: 3GEY) and the EGFR tyrosine kinase receptor (code: 1m17).

Study of Synthesis, Characterization, DFT, and In Vitro Biological Activity of Cu(II), Co(II), and Fe(II) Metal Complexes Based on Heterocyclic Azo Pyrazole Dye Ligand

A new azo dye ligand was synthesized by coupling 5-amino-3-methyl-1-phenylpyrazole with a diazonium ion of 2-amino-1-naphthalene sulfonic acid. Its Co(II), Fe(II), and Cu(II) complexes were also synthesized. This ligand and its complexes were characterized based on elemental analysis, IR, 1H NMR, UV-vis spectra, and thermogravimetric analysis. The data showed that the proposed complexes have an octahedral geometry around the central metal ion. The nonelectrolytic nature of the complexes was confirmed by molar conductance measurement. X-ray powder diffraction indicates that Co(II) and Fe(II) complexes are amorphous in nature, whereas the Cu(II) complex has crystalline and amorphous phases. The bond strength and molecular stability between the interaction of metal ions and the ligand were investigated by density functional theory (DFT). The in vitro antibacterial activity of the ligand and complexes was tested against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Neisseria gonorrhoeae) and a fungus (Candida albicans). The Cu(II) complex exhibited a high antimicrobial effect against all tested microorganisms. The DNA fragmentation percentage and cytotoxic activity against human liver cancer cells (HepG2) were evaluated. All tested compounds showed potential anticancer activity, and the Co(II) complex showed better activity results than the other tested compounds, with IC50 = 19.55 μg/mL.

A review on the chemistry of novel platinum chelates based on azo-azomethine ligands

Numerous platinum group metals (PGMs) complexes contain azo-azomethine-based ligands. Azo-azomethine ligands are N-donor ligands that have extended conjugated π-bonded systems and both azo (–N=N–) and aldimine (–C=N–) functions in their structure. Plenty of platinum (Pt) complexes with azo-imine ligands have been prepared and characterized. Various multidentate azo-imine ligands coordinated with different platinum metal substrates afforded structurally diverse platinum chelates. Nonetheless, many azo-imine-based platinum complexes demonstrated a wide range of biological activities, photo-switchable properties, and redox activities. The review encompasses a general overview of platinum complexes with versatile azo-azomethine ligands, their synthetic protocol, spectroscopic and structural features, chemical reactivity, and multipurpose applications in different areas.