Synthesis, Characterization, Antimicrobial, Density Functional Theory, and Molecular Docking Studies of Novel Mn(II), Fe(III), and Cr(III) Complexes Incorporating 4-(2-Hydroxyphenyl azo)-1-naphthol (Az)

This work synthesized three new CrAz₂, MnAz₂, and FeAz₂ complexes and investigated them using IR, mass, UV spectroscopy, elemental analysis, conductivity and magnetic tests, and thermogravimetric analysis. The azo-ligand, 4-(2-hydroxyphenylAzo)-1-naphthol (Az), couples with metal ions via its nitrogen (in -N=N- bonds) and oxygen (in hydroxyl group) atoms, according to the IR spectra of these complexes. Through thermal examination (TG/TGA), the number and location of water in the complexes were also determined. Density functional theory (DFT) theory is applied to ameliorate the structures of the ligand (Az) and metal complexes and analyze the quantum chemical characteristics of these complexes. The antifungal and antibacterial activity of the ligand and its complexes opposed to several hazardous bacteria and fungi was investigated in vitro. Metal complexes were discovered to have a higher inhibitory impact on some organisms than the free ligand. The MnAz₂ complex exhibited the best activity among the studied materials, whereas the CrAz₂ complex had the lowest. The compounds' binding affinity to the E. coli (PDB ID: 1hnj) structure was predicted using molecular docking. Binding energies were calculated by analyzing protein-substrate interactions. These encouraging findings imply that these chemicals may have physiological effects and may be valuable for a variety of medical uses in the future.

Theoretical Investigation by DFT and Molecular Docking of Synthesized Oxidovanadium(IV)-Based Imidazole Drug Complexes as Promising Anticancer Agents

Vanadium compounds have been set in various fields as anticancer, anti-diabetic, anti-parasitic, anti-viral, and anti-bacterial agents. This study reports the synthesis and structural characterization of oxidovanadium(IV)-based imidazole drug complexes by the elemental analyzer, molar conductance, magnetic moment, spectroscopic techniques, as well as thermal analysis. The obtained geometries were studied theoretically using density functional theory (DFT) under the B3LYP level. The DNA-binding nature of the ligands and their synthesized complexes has been studied by the electronic absorption titrations method. The biological studies were carried with in-vivo assays and the molecular docking method. The EPR spectra asserted the geometry around the vanadium center to be a square pyramid for metal complexes. The geometries have been confirmed using DFT under the B3LYP level. Moreover, the quantum parameters proposed promising bioactivity of the oxidovanadium(IV) complexes. The results of the DNA-binding revealed that the investigated complexes bind to DNA via non-covalent mode, and the intrinsic binding constant (K_b) value for the [VO(SO₄)(MNZ)₂] H₂O complex was promising, which was 2.0 × 10⁶ M⁻¹. Additionally, the cytotoxic activity of the synthesized complexes exhibited good inhibition toward both hepatocellular carcinoma (HepG-2) and human breast cancer (HCF-7) cell lines. The results of molecular docking displayed good correlations with experimental cytotoxicity findings. Therefore, these findings suggest that our synthesized complexes can be introduced as effective anticancer agents.

Synthesis and characterization of Cu(II)-pyrazole complexes for possible anticancer agents; conformational studies as well as compatible in-silico and in-vitro assays

New pyrazole derivatives were prepared and used to synthesize new bioactive agents from Cu(II) complexes that have OSN donors. Analytical and spectral (IR, UV-Vis, MS, ¹H NMR, ESR & XRD) instruments characterized these complexes as well as their corresponding ligands. The bonding mode has been modified from ligand to ligand and the molar ratio for isolated complexes has also varied (1:1/1:2, M:L). The geometry of isolated complexes was commonly proposed, based on electronic transitions and ESR spectral-parameters. Via computational approaches, these structures were optimized using standard programs (Gaussian 09 & HyperChem 8.1) under the required basis set. Consequently, important physical characteristics have been obtained after finishing the optimization process. Inhibition behavior of all new synthesizes was studied by MOE module as in-silico approach which conducted versus the crystal structure of NUDT5 protein (6gru) of breast cancer cells. The interaction features summarized from docking processes, reveal effective inhibition validity for new Cu(II) complexes versus breast cancer cells. This according to scoring energy values and the stability of docking complexes in true interaction path (bond length ≤3.5 Å) particularly with Cu(II)-L³ and Cu(II)-L⁴ complexes. This reflects the possibility of successful behavior during practical application through in-vitro assay that intended in this study. Finally, the degree of toxicity of such new compounds to the breast cancer cell line was determined by in-vitro screening. To judge perfectly on their toxicity, in-vitro screening must compared to positive control as Doxorubicin (reference drug). IC₅₀ values were calculated and represent Cu(II) complexes as outstanding cytotoxic agents which revealed superiority on the reference drug itself.

Complexation of uranyl (UO2)2+ with bidentate ligands: XRD, spectroscopic, computational, and biological studies

Three new uranyl complexes [(UO₂)(OAc)₂(CMZ)], [(UO₂)(OAc)₂(MP)] and [(UO₂)(OAc)₂(SCZ)] were synthesized and characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, powder XRD analysis, and molar conductivity. The IR analysis confirmed binding to the metal ion by the sulfur and ethoxy oxygen atoms in the carbimazole (CMZ) ligand, while in the 6-mercaptopurine (MP) ligand, the sulfur and the N7 nitrogen atom of a purine coordinated binding to the metal ion. The third ligand showed a 1:1 molar ratio and bound via sulfonamide oxygen and the nitrogen of the pyrimidine ring. Analysis of the synthesized complexes also showed that acetate groups had monodentate binding to the (UO₂²⁺). Density Functional Theory (DFT) calculations at the B3LYP level showed similar structures to the experimental results. Theoretical quantum parameters predicted the reactivity of the complexes in the order, [(UO₂)(OAc)₂(SCZ)] > [(UO₂)(OAc)₂(MP)]> [(UO₂)(OAc)₂(CMZ)]. DNA binding studies revealed that [(UO₂)(OAc)₂(SCZ)] and [(UO₂)(OAc)₂(CMZ)] have the highest binding constant (K_b) among the uranyl complexes. Additionally, strong binding of the MP and CMZ metal complexes to human serum albumin (HSA) were observed by both absorbance and fluorescence approaches. The antibacterial activity of the complexes was also evaluated against four bacterial strains: two gram-negative; Escherichia coli and Klebsiella pneumonia, and two gram-positive; Staphylococcus aureus and Streptococcus mutans. [(UO₂)(OAc)₂(MP)] had the greatest antibacterial activity against Klebsiella pneumonia, the gram-positive bacteria, with even higher activity than the standard antibiotic. In vitro cytotoxicity tests were also performed against three human cancer lines, and revealed the most cytotoxic complexes to be [(UO₂)(OAc)₂(SCZ)], which showed moderate activity against a colon cancer cell line. Thus, uranyl addition enhances the antibacterial and anticancer properties of the free ligands.