New mononuclear Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes incorporating 4‐{[(2 hydroxyphenyl)imino]methyl}phenyl‐4‐methylbenzenesulfonate (HL): Synthesis, characterization, theoretical, anti‐inflammatory, and molecular docking investigation

Iron-Imine Cocktail in Drug Development: A Contemporary Update

Organometallic drug development is still in its early stage, but recent studies show that organometallics having iron as the central atom have the possibility of becoming good drug candidates because iron is an important micro-nutrient, and it is compatible with many biological systems, including the human body. Being an eco-friendly Lewis acid, iron can accept the lone pair of electrons from imino(sp2)-nitrogen, and the resultant iron-imine complexes with iron as a central atom have the possibility of interacting with several proteins and enzymes in humans. Iron-imine complexes have demonstrated significant potential with anticancer, bactericidal, fungicidal, and other medicinal activities in recent years. This article systematically discusses major synthetic methods and pharmacological potentials of iron-imine complexes having in vitro activity to significant clinical performance from 2016 to date. In a nutshell, this manuscript offers a simplistic view of iron complexes in medicinal inorganic chemistry: for instance, iron is presented as an "eco-friendly non-toxic" metal (as opposed to platinum) that will lead to non-toxic pharmaceuticals. The abundant literature on iron chelators shows that many iron complexes, particularly if redox-active in cells, can be quite cytotoxic, which can be beneficial for future targeted therapies. While we made every effort to include all the related papers, any omission is purely unintentional.

Novel 2-Acetamido-2-ylidene-4-imidazole Derivatives (El-Saghier Reaction): Green Synthesis, Biological Assessment, and Molecular Docking

El-Saghier reaction is the novel, general, and green reaction of various amines with ethyl cyanoacetate and ethyl glycinate hydrochloride. A new series of imidazolidin-4-ones and bis-N-(alkyl/aryl) imidazolidin-4-ones was synthesized in a sequential, one-pot procedure under neat conditions for 2 h at 70 °C. Excellent high yields (90-98%) were achieved in a short period of time while avoiding issues related to the hazardous solvents utilized (cost, safety, and pollution). The spectrum analyses and elemental data of the newly synthesized compounds helped us to clarify their structures. The obtained compounds were tested for antibacterial activity in vitro and compared to the standard antibiotic chloramphenicol as the standard, measuring the inhibition zone (nm) and activity index (%). With an antibacterial percentage value of 80.0 against Escherichia coli, N,N'-(propane-1,3-diyl) bis(2-(4-oxo-4,5-dihydro-1H-imidazole-2-yl) acetamide) proved to be the most effective. Antimicrobial activity was confirmed by a molecular docking investigation to investigate how chemicals bind to the bacterial FabH-CoA complex in E. coli (PDB ID: 1HNJ).

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.

Designing, characterization, biological, DFT, and molecular docking analysis for new FeAZD, NiAZD, and CuAZD complexes incorporating 1-(2-hydroxyphenylazo)- 2-naphthol (H2AZD)

Herien, three new Fe(III) (FeAZD), Ni(II) (NiAZD), and Cu(II) (CuAZD) complexes were synthesized and characterized using various physicochemical and spectroscopic approaches. The H₂AZD ligand acted as a bi-basic bi-dentate NO ligand in a 1:1 molar ratio. The results revealed that the FeAZD and CuAZD complexes had octahedral geometry, while the NiAZD had a tetrahedral geometry. The optimized geometry, HOMO and LUMO analysis of the ligand and its metal complexes was determined via Density functional theory (DFT) using the B3LYP with 6-311 G(d,p), and LanL2DZ level of theory. The FeAZD, NiAZD and CuAZD had lower energy gap, 7.40, 7.93 and 7.06 eV, respectively, than the free ligand (9.58 eV), which proposed that CuAZD was more active one. The free ligand and its metal complexes were in vitro investigated for their antibacterial and antifungal activity. The results illustrated that the metal complexes had higher antibacterial and antifungal activity than the free ligand. More specifically, the CuAZD demonstrated good antibacterial activity against E. coli, P. aeruginosa, S. aureus, B. cereus, and A. flavus, T. rubrum, and C. albicans, with activity indexes of 72.22%, 65.01%, 77.78%, and 72.22%, 63.16%, 59.09%, and 61.90%, respectively. Also, the metal complexes showed lower MIC (6.25-3.125 ppm) compared to the free ligand (about 50 ppm). Finally, molecular docking was utilized to investigate the ability of the free ligand and its metal complexes to inhibit the growth of E. coli (PDB ID: 5iq9). The results showed that the CuAZD had the highest binding affinity to the receptor, with a more negative docking score of - 7.05 Kcal/mol, and lower inhibition constant (Ki) of 6.90 µM. That is indicating that it may be the most effective at inhibiting the growth of E. coli (PDB ID: 5iq9).

Design, Synthesis, Spectroscopic Inspection, DFT and Molecular Docking Study of Metal Chelates Incorporating Azo Dye Ligand for Biological Evaluation

A new heterocyclic azo dye ligand (L) was synthesized by the combination of 4-amino antipyrine with 4-aminophenol. The new Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes were synthesized in excellent yields. The metal chelate structures were elucidated using elemental analyses, FT-IR, ¹H-NMR, mass, magnetic moment, diffused reflectance spectral and thermal analysis (TG-DTG), and molar conductivity measurement. According to the FT-IR study, the azo dye ligand exhibited neutral tri-dentate behavior, binding to the metal ions with the azo N, carbonyl O, and protonated phenolic OH. The ¹H-NMR spectral study of the Zn(II) complex supported the coordination of the zo dye ligand without proton displacement of the phenolic OH. Diffused reflectance and magnetic moment studies revealed the octahedral geometry of the complexes, as well as their good electrolytic nature, excepting the Zn(II) and Cd(II) complexes, which were nonelectrolytes, as deduced from the molar conductivity study. The theoretical calculations of optimized HOMO-LUMO energies, geometrical parameters, electronic spectra, natural atomic charges, 3D-plots of MEP, and vibrational wavenumbers were computed and elucidated using LANL2DZ and 6-311G (d, p) basis sets of density functional theory (DFT) with the approach of B3LYP DFT and TD-DFT methods. The ligand and complexes have been assayed for their antimicrobial activity and compared with the standard drugs. Most of the complexes have manifested excellent antimicrobial activity against various microbial strains. A molecular docking investigation was also performed, to acquire more information about the binding mode and energy of the ligand and its metal complexes to the Escherichia coli receptor using molecular docking. Altogether, the newly created ligand and complexes showed positive antibacterial effects and are worth future study.

Synthesis, DFT, Biological and Molecular Docking Analysis of Novel Manganese(II), Iron(III), Cobalt(II), Nickel(II), and Copper(II) Chelate Complexes Ligated by 1-(4-Nitrophenylazo)-2-naphthol

Novelmanganese(II), iron(III), cobalt(II), nickel(II), and copper(II) chelates were synthesized and studied using elemental analysis (EA), infrared spectroscopy, mass spectrometry, ultraviolet-visible spectroscopy, and conductivity, as well as magnetic measurements and thermogravimetric analysis (TG). The azo-ligand 1-[(4-nitrophenyl)diazenyl]-2-naphthol (HL) chelates to the metal ions via the nitrogen and oxygen centers of the azo group and the hydroxyl, respectively. The amounts of H₂O present and its precise position were identified by thermal analysis. Density functional theory (DFT) was employed to theoretically elucidate the molecular structures of the ligand and the metal complexes. Furthermore, the quantum chemical parameters were also evaluated. The antimicrobial properties were evaluated against a group of fungal and bacterial microbes. Interestingly, the bioactivity of the complexes is enhanced compared to free ligands. Within this context, the CuL complex manifested the lowest activity, whereas the FeL complex had the greatest. Molecular docking was used to foretell the drugs' binding affinity for the structure of Escherichia coli (PDB ID: 1hnj). Protein-substrate interactions were resolved, and binding energies were accordingly calculated.