Mononucleating nicotinohydazone complexes with VO2+, Cu2+, and Ni2+ ions. Characteristic, catalytic, and biological assessments

Comprehensive analysis of the electronic, thermodynamic, and spectroscopic properties of a Cu(II)-based complex with 1,10-phenanthroline and L-glutamine

This study reports additional information's of geometric, electronic, thermodynamic, and vibrational properties of a Cu(II) complex with 1,10-phenanthroline and L-glutamine ligands. The experimental spectroscopic analyses were corroborated by density functional theory (DFT). Furthermore, these properties were evaluated using an implicit solvation method with water and methanol solvents, including vacuum condition. The theoretical predictions provided a deeper understanding of the frontier molecular orbitals, chemical reactivity indices, dipole moment, and electrostatic potential maps. A computational analysis of the intermolecular interactions using Hirshfeld surfaces was also performed, which demonstrated that the H⋯O/O⋯H and H⋯H interactions are mainly responsible for the structural and thermal stability of the complex. The calculated intramolecular vibration bands showed a good correlation with the experimental Raman and infrared (IR) data, although solvation effects caused some wavenumber shifts. In vitro, antitumor assays were performed to evaluate the cytotoxic effects of the complex against prostate (PC-3) and glioblastoma (SNB-19) cancer cells. Absorption, distribution, metabolism, and excretion (ADME) parameters, along with drug-like properties, are also presented in this work.

Deciphering the Mechanism of MRSA Targeting Copper(II) Complexes of NN2 Pincer-Type Ligands

WHO lists AMR as one of the top ten global public health issues. Therefore, constant effort is needed to develop more efficient antimicrobial drugs. As a result, earth-abundant transition-metal complexes have emerged as an excellent solution. In this regard, new aminoquinoline-based copper(II) pincer complexes 1-3 were designed, synthesized, and characterized by modern spectroscopic techniques. It is worth mentioning that, at the highest concentration (1024 μg/mL) of complexes (1-3), the hemolysis was found to be <15%, implying their less toxicity. Further, the complexes effectively interfered with the growth of Gram positive MRSA and the fungus Candida albicans. Among them, complex 2 was promising (MIC = 16 μg/mL) against MRSA, which was better than the known antibacterial drug kanamycin (64 μg/mL) under identical conditions. The Alamar blue cell viability test and the MBC/MFC identified by spot assay were in accordance with MIC values. Moreover, the insilico studies explained the most probable mechanism of action as inhibition of cell wall biosynthesis and dysfunction of antibiotic sensing proteins. Similarly, the antifungal action might be due to the cell surface adhesion protein dysfunction by the complexes. Furthermore, we are expecting to draw these compounds for clinical applications.

Bioreactivity of divalent bimetallic vanadyl and zinc complexes bis-oxalyldihydrazone ligand against microbial and human cancer series. ctDNA interaction mode

Two novel divalent bimetallic complexes were constructed from the complexation of O=V4+ and Zn2+ ions (VOL and ZnL), respectively, with diisatin oxalyldihydrazone ligand (H2L). Various spectroscopic tools were used to confirm their chemical structures (FT-IR, NMR, EI-Mass, and electronic spectra), besides, elemental analyses and conductivity features. To estimate the role of divalent metal ions in their coordination compound for developing their bio-reactivity, the free ligand H2Lox, and its complexes (VOL and ZnL) were employed spectroscopic investigations against the growth of some microbial series (fungi and bacteria) and also against three human cancer/normal cells. Furthermore, their interaction behavior against calf thymus DNA (ctDNA) was studied through viscometric and spectrophotometric studies to discover the role of O=V4+ and Zn2+ ions to determine the mode of binding with ctDNA. The inhibiting effect of H2L, VOL, and ZnL versus the titled microbial (bacterial and fungal) was built upon their inhibited zone areas in mm and the MIC concentrations in μM. Their action against the three human cancer cells' growth was evaluated by IC50 values in μM and the selectivity index in percentage. Both VOL and ZnL complexes exhibited an amazing series with three human cancer cell growth (according to the zone values in mm of inhibition, MIC in μM, and IC50 values in μM) compared to those of their uncoordinated H2L ligand. VOL demonstrated a distinguished interacting behavior with ctDNA more than that interaction of ZnL depending on the variation of the central metal ion chemical features. Within the covalent and non-covalent interaction modes, the interaction binding between H2L, VOL, and ZnL with ctDNA was discussed based on the electronic spectroscopic observation.

Pincer Complexes Derived from Tridentate Schiff Bases for Their Use as Antimicrobial Metallopharmaceuticals

Within the current challenges in medicinal chemistry, the development of new and better therapeutic agents effective against infectious diseases produced by bacteria, fungi, viruses, and parasites stands out. With chemotherapy as one of the main strategies against these diseases focusing on the administration of organic and inorganic drugs, the latter is generally based on the synergistic effect produced by the formation of metal complexes with biologically active organic compounds. In this sense, Schiff bases (SBs) represent and ideal ligand scaffold since they have demonstrated a broad spectrum of antitumor, antiviral, antimicrobial, and anti-inflammatory activities, among others. In addition, SBs are synthesized in an easy manner from one-step condensation reactions, being thus suitable for facile structural modifications, having the imine group as a coordination point found in most of their metal complexes, and promoting chelation when other donor atoms are three, four, or five bonds apart. However, despite the wide variety of metal complexes found in the literature using this type of ligands, only a handful of them include on their structures tridentate SBs ligands and their biological evaluation has been explored. Hence, this review summarizes the most important antimicrobial activity results reported this far for pincer-type complexes (main group and d-block) derived from SBs tridentate ligands.

Preparation of Cu(II), Ni(II), Ti(IV), VO(IV), and Zn(II) Metal Complexes Derived from Novel vic-Dioxime and Investigation of Their Antioxidant and Antibacterial Activities

In this work, novel vic-dioxime ligand (LH₂ ) containing bound to the N₄ -oxime core moiety and its complexes with Cu(II), Ni(II), Ti(IV), VO(IV), and Zn(II) salts have been studied. The structure of the ligand and its complexes were successfully synthesized and characterized using NMR (¹ H and ¹³ C), LC/MS/MS spectrometer, FT-IR and UV/VIS spectroscopy, melting point, and magnetic susceptibility measurements. Vic-dioxime ligand (LH₂ ) (1) and its metal complexes ([Cu(LH)₂ ] (2), [Ni(LH)₂ ] (3), [Ti(LH)₂ ]Cl₂ (4), [VO(LH)₂ ] (5), and [Zn(LH)₂ ] (6), respectively) were tested for them in-vitro antibacterial and antioxidant activities. According to the metal chelating results of the study, it was determined that compounds (1), (2), (3), and (6) showed very good activity, and especially compound (2), had a stronger metal chelating capacity due to ligand dissociation from the synthesized metal complexes, which then would chelate Fe(II) in the experimental setting. When microorganisms were evaluated in terms of the % viability effect, it was observed that all compounds had activity against C. Albicans and S. Cerevisiae at rates similar to antibiotics.

Synthesis, spectral characterization, DFT calculations, pharmacological studies, CT-DNA binding and molecular docking of potential N, O-multidentate chelating ligand and its VO(II), Zn(II) and ZrO(II) chelates

The pharmacological efficacy of the variety tetradentate ligands encouraged us to design attractive compounds through effective synthetic procedure. The prepared Schiff base ligand 6,6'-((1E,1'E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methaneylylidene))bis(2-ethoxy phenol (H₂L), which derived from 4-chloro-o-phenylenediamine and 3-ethoxy-salicylaldehyde and its VO(II), Zn(II) and ZrO(II) metal chelates, have been synthesized and characterized with aim of that it may struggle the invasion of drug resistance. The chemical structural of studied compounds were discussed by TGA, elemental analysis, UV-Vis., ¹H NMR, ¹³C NMR, FTIR, mass spectral, PXRD, molar conductance, magnetic susceptibility measurements and density functional theory. The results assigned square pyramid geometries for [VOL] and [ZrOL].2H₂O chelates and an octahedral geometry for [ZnL(H₂O)₂].2H₂O chelate. Powder XRD data showed that the complexes are monoclinic with polycrystalline nature. The results of CT-DNA interaction with the titled chelates showed that the binding between CT-DNA and the metal complexes occurs through intercalation mode. Their CT-DNA binding efficiency estimated in terms of their binding constants (K_b), which gave the order: VOL (6.9 × 10⁵) > ZrOL (6.3 × 10⁵) > ZnL(H₂O)₂ (5.5 × 10⁵). The antimicrobial activities of the synthesized compounds were tested against selected fungal and bacterial strains using well diffusion technique. The obtained chelates showed higher antifungal and antibacterial activities than their corresponding ligand. Furthermore, the M-complexes showed higher potent cytotoxic effect toward HEK-293, human colorectal HepG-2, HCT-116 and MCF-7 adenocarcinoma cell lines compared to the free H₂L ligand. Investigation of antioxidant property represented that all the prepared complexes have better radical scavenging potencies against DPPH radicals than the free H₂L ligand. To study the molecular docking of proposed compounds versus Tyrosine kinases receptor (TKR), we used AutoDock1.5.6rc3® suite. The current compounds (H₂L, VOL, ZrOL and ZnL(H₂O)₂) and STI were found to bind with C-kit of TKR with HBs at ILE789.A, ILE808.A, ASP810.A, GLU640.A and TYR846 amino acid residue and the binding energies were - 8.9, -8.93, -8.83, -1.48 and -10.39 kcal/mol respectively.