Newly synthesised Schiff base metal complexes, characterisation, and contribution as enhancers of colon cancer cell apoptosis by overexpression of P53 protein

A water‐soluble hydrazone ligand bearing 2‐nicotinoylhydrazineylidene moiety, sodium 4‐hydroxy‐3‐([2‐nicotinoylhydrazineylidene]methyl) benzenesulfonate (NaH2NH), and its complexes with Co(II), Fe(III), and Mn(II) have been synthesized and characterized. The structure of the ligand and its complexes were analyzed using various spectroscopic techniques such as FT‐IR, 1H‐ and 13C‐NMR, EI‐mass, powder X‐ray diffraction, UV–visible spectra, and magnetic measurements. The infrared spectra indicated that the ligand behaves as a negatively charged bidentate ligand (ON) through the deprotonation of the enolic (OH) group and the azomethine (C=N) group in the [Co (NaHNH)2(H2O)4Cl2].3H2O complex. In the [Fe (NaNH)2(H2O)Cl].2H2O complex, the ligand behaves as bi‐negative tetradentate (O2N2) through the protonation of the enolic oxygen and the nitrogen atom of the azomethine group in two nicotinic hydrazone molecules. Another coordination type was observed for [Mn (NaNH)(H2O)3] complex in which NaH2NH acts as bi‐negative tridentate ONO through the nitrogen atom of the azomethine group, the protonated of enolic and phenolic groups. The fluorescence spectrum of the NaH2NH was found to be quenched upon addition of these Co(II) and Mn(II) ions. The antimicrobial results indicated that the Mn(II) complex exhibited the highest antibacterial potency against all targeted organisms. The results of antioxidants demonstrated that the complexes exhibited higher activity compared to the free ligand, indicating an enhancement of antioxidant activity through complexation. The tested substances established strong nuclease‐like activity at a high concentration of 7.5 mM, leading to the complete degradation of DNA as observed in agarose gel electrophoresis. This suggests that these compounds have the potential to serve as antitumor agents in vivo by inhibiting DNA replication in cancer cells and preventing tumor growth. The interaction of the isolated compounds with 1c14 and 6vj3 targets was discussed using molecular docking.

Co(II), Mn(II), and Fe(III) complexes of water‐soluble hydrazone bearing 2‐nicotinoylhydrazineylidene moiety: Preparation, characterization, cyclic voltammetry, computational and biological studies

Mohammed,

Fetoh,

Ali

et al. 2024

Innovation of some novel complexes based on 1‐(4‐nitrophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methanol ligand: Synthesis, structural elucidation DFT calculation and pharmaceutical studies

Al‐Abdulkarim,

Qasem,

Aouad

et al. 2024

Novel divalent chelates of Co (II), Cu (II), Zn (II) and Ni (II) were prepared and described of the form [M (NTM)(CH3COO)2] where NTM = [1‐(4‐nitrophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methanol ligand. Elemental analyses, infrared red, 1H and 13CNMR, electronic, magnetic susceptibility, conductivity measurements and X‐ray diffraction studies were used to assess our divalent metal complexes. Moreover, the stability and stoichiometry of the novel metal chelates were examined through the job's method in solutions. Correlation of all spectroscopic techniques states that NTM acts as a bi‐dentate NO ligand to afford octahedral complex geometry for all the investigated metal chelates. Thermodynamic and kinetics factors for various thermal degradation phases were calculated. Moreover, B3LYP/LANL2DZ/6‐311 g(d,p) theoretical study has been applied for estimating the MEP and quantum chemical reactivity descriptors of studied molecules. Moreover, the UV–Vis absorption spectra for the investigated molecules are predicted via the time‐dependent DFT (TD‐DFT) calculations. In addition, MOE‐ docking was tested on two different proteins, the receptor of (3HB5) breast cancer mutant oxidoreductase as well as the receptor of Glucosamine‐6‐phosphate synthase in complex with glucosamine‐6‐ phosphate of (2VF5) E.coli and COVID‐19 protease. The results recommended that the (NTMCo), (NTMNi), (NTMCu) and (NTMZn) complexes showed the highest inhibitory activity compared to the other NTM ligands as antimicrobial and breast cancer candidates. Furthermore, in‐vitro anti‐bacterial, anti‐fungal, cytotoxic and anti‐oxidant performances for the selected ligand as well as its chelates were studied. All metal chelates presented superiority, proceeding free organic ligand ineffective management, definitely NTMCu complex.

Design, characterization, and different applications of naphthoquinone‐based Schiff base and its M(II/III) complexes with molecular modeling studies

Saleh,

Alminderej,

El‐Sayed

et al. 2024

Due to the significant pharmacophoric role of 1,4‐naphthoquinone moiety, which is found in numerous biologically active natural products and well‐known chemotherapeutic drugs, including doxorubicin, shikonin, and alkannin, a newly prepared ligand ((E)‐1‐((2‐mercaptophenyl)imino)naphthalen‐2(1H)‐one) can be obtained from the condensation of 2‐aminothiophenol with diketone (1,2‐naphthoquinone) to form Schiff base (HL), which has been characterized using elemental analyses, FT‐IR, 1H‐NMR, and mass spectra. The inner ((La(III), Er(III), and Yb(III)) and outer ((Fe(III), Co(II), and Zn(II)) transitionmetal complexes have been prepared in 1:2 ratio and identified by several spectroscopic instruments. Different characterization tools have been used as elemental analyses, 1H‐NMR, molar conductivity, 13C‐NMR, FT‐IR, thermal decomposition (TG and DTG), UV‐vis, X‐ray diffraction, mass spectrometry, solid reflectance, and magnetic moment. All of them are conjugated to confirm the proposed structures of the metal complexes and are complementary. Also, molecular docking studies for the ligand and its Zn(II) and Yb(III) complexes (using MOE program) have been performed to support the experimental biological activity. Molecular docking studies recommended that (Yb(HL)2)Cl3·6H2O complex is more potent against Aspergillus niger fungus when docked with 1Y43 (aspergilloglutamic peptidase enzyme from A. niger) receptor, while Zn(II) complex recorded the strongest binding energy among the docked compounds against 2W3Z(the crystal structure of a Streptococcus mutans CE4 esterase) and 7AB4 (the crystal structure of the Escherichia coli toxin‐antitoxin system HipBST [HipT S59A]) proteins receptors, respectively. Experimental applications of the free ligand and its metal chelates as antimicrobial and antioxidant activities have been carried out. The former occurred against two fungal species (Aspergillus niger [ATCC:16404] and Candida albicans [ATCC:10231]), two G‐positive bacterial species (S. mutans [ATCC:25175] and Staphylococcus aureus [ATCC:13565]) and two G‐negative bacterial species (Klebsiella pneumonia [ATCC:10031] and E. coli [ATCC:10536]). The DPPH scavenging method has been used to measure the antioxidant activity of the tested compounds.