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Introduction: This study focuses on the development of novel antimicrobial agents. A Schiff base ligand, 6-(2-(4-hydroxy-3-methoxybenzylideneamino)-2-(4-hydroxyphenyl)acetamido)-3,3-dimethyl-7-oxo- 4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid, synthesized through the condensation of amoxicillin and vanillin in methanol, served as the foundation. Polydentate mixed ligand complexes were then formed by reacting the Schiff base with metal ions (Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)) and nicotinamide in specific ratios., Methods: Characterization involved various techniques, such as 1 H-NMR, FT-IR, UV-Vis, and elemental analysis for the ligand, and Atomic Absorption, FT-IR, UV-Vis, magnetic susceptibility, and conductance measurements for the Schiff base-metal ion complexes., Results: Quantum chemical features of both ligands and metal complexes were computed, refining their electronic and molecular structures theoretically. Antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Acinetobacter baumannii , and Pseudomonas aeruginosa was assessed for the starting materials, ligands, and synthesized complexes, revealing significant effects on certain species. In-silico binding modes with Escherichia coli (PDB ID: 5iq9) were determined through molecular docking., Conclusion: This study underscores the potential applications of the Schiff base ligands and their metal complexes in developing new antimicrobial agents., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

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. [ABSTRACT FROM AUTHOR]

The primary objective of the current framework was to synthesize novel mononuclear 1:1:1 complexes involving FeLG, CoLG, NiLG, CuLG, and ZnLG, where the ligand (L) is identified as 4-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl)hydrazono]methylphenyl-4-methylbenzenesulfonate, and glycine (G) serves as the coligand. Comprehensive characterization of the investigated complexes was achieved through various analytical techniques, including FTIR, UV-Vis spectroscopy, elemental analysis, mass spectra, magnetic susceptibility measurements, molar conductivity assessments, and thermogravimetric analysis (TGA). The determination of stoichiometry was performed employing the molar ratio technique, revealing the octahedral geometry inherent in the isolated metal complexes. Employing a density functional theory (DFT) approach, the molecular structures of the designated compounds were theoretically elevated, and quantum chemical descriptors were derived to provide a deeper insight into their electronic properties. Furthermore, the inhibitory potential of these compounds against fungal strains and pathogenic bacteria prevalent in the Arab environment was evaluated using the disc diffusion method, emphasizing their role in combating diseases affecting humans, animals, and plants. Notably, the metal complexes exhibited superior antibacterial activity, as evidenced by a higher activity index. Molecular docking investigations were conducted to ascertain the inhibitory effects of the compounds on the 1FJ4 protein, with ZnLG emerging as the compound with the highest binding affinity. These results suggest the promising candidacy of these compounds as antimicrobial agents, particularly in the context of combating bacterial and fungal infections. [ABSTRACT FROM AUTHOR]

New 2-[(4-[(4-methylphenyl)sulfonothioyl)methylene]aminobenzoic acid ligand-Co(II), Ni(II), and Cu(II) complexes are synthesized and characterized in this article. Elemental analysis, mass spectroscopy, conductivity tests, magnetic susceptibility, Fourier transform infrared spectroscopy, thermogravimetric analysis, electronic absorption spectroscopy, and density functional theory calculations were used to determine the coordination mode, and geometry of the synthesized compounds. The Schiff-base ligand was shown to be mononegatively charged and coordinate to metal ions in a bi-dentate mode through azomethine nitrogen (-CH=N-) and carboxylic Oxygen (-COOH). Density functional theory (DFT) calculations were performed in addition to the experimental data to assess the most probable structures of the complexes. In addition, the biological activities of these compounds were evaluated by in vitro antibacterial and antifungal assays. These novel Co(II), Ni(II), and Cu(II) compounds were shown to be active against a wide variety of microorganisms, including Gram-positive and Gram-negative bacteria, as well as fungi. Following that, molecular docking was used to analyze the complexes' interactions with bacterial proteins, validating the therapeutic potential of the metal-containing compounds. [ABSTRACT FROM AUTHOR]

The aim of the present framework is to synthesize and characterize new cobalt(II) (C1), nickel(II) (C2), and copper(II) (C3) mixed‐ligand complexes incorporating bioactive 8‐hydroxyquinoline moiety, with synthesized 2‐(1H‐benzimidazol‐2‐yl)guanidine (BG) ligand, for investigating their antibacterial, antifungal, and anti‐inflammatory potential. The metal complexes structure had been elucidated by the use of a wide range of methods, including elemental analysis, Fourier transform infrared (FT‐IR), mass spectra, UV–vis spectra, magnetic susceptibility, thermogravimetric (TG) analysis, and the molar ratio technique of stoichiometry analysis. The resulted metal complexes were found to have octahedral structures in molar ratio of M:BG:Qu as 1:1:2. Density functional theory (DFT) had been used to determine the optimal molecular structure and quantum chemical properties of each material. After that, we looked into the metal complexes' anti‐inflammatory and antibacterial properties by testing them in vitro. The disc diffusion test showed that the metal complexes were far more potent against bacteria/fungi than the original ligands. The egg albumin denaturation technique showed that the metal complexes were more potent anti‐inflammatory candidates than the free ligands and comparable with the standard reference. Molecular docking analysis against 5JQ9, 6CLV, and cyclooxygenase‐2 (COX‐2; 5IKT) confirmed the bioactivity behavior of the metal complexes. C3 has the greatest binding affinity among the metal complexes tested. These findings proposed that the metal complexes could form the basis of future antibiotics and anti‐inflammatory candidates. Finally, the in vitro activities were reviewed in relation to the DFT and molecular docking data. [ABSTRACT FROM AUTHOR]

The main purpose of the current work is the design and synthesis of new Co(II), Ni(II), and Cu(II) mixed‐ligand complexes derived from simple and easily synthesized azo‐ligand, [2‐(phenylthio)phenyl]diazenyl}‐2‐naphthol (HTe), with 8‐hydroxyquinoline (HQ) to improve and understanding their action as an antimicrobial candidate and their therapeutic efficiency with the aid of density functional theory (DFT) calculations and molecular docking studies, which considered a hot topic of research. To access this target, and to explore the effect of changing metal ion type, the new Co(II), Ni(II), and Cu(II) mixed‐ligand complexes were firstly synthesized and characterized via elemental analysis, Fourier transform infrared (FT‐IR), mass spectrometry, ultraviolet–visible spectroscopy, magnetic susceptibility, thermogravimetric analysis (TGA), and stoichiometry analysis molar ratio method. Upon further inspection, the octahedral structures of the isolated metal complexes were found. The compounds' molecular structures were optimized using the DFT technique, and the quantum chemical parameters were evaluated. To determine whether or not these compounds are effective in preventing the spread of harmful bacteria and fungi, two of the most common environmental pollutants in the Arab world, a disc diffusion test was conducted. The prepared complexes were much more efficient against bacteria than the pristine ligands. Molecular docking experiments helped researchers learn which medicines inhibited the 1fj4 protein. All other tested compounds were found to have lower binding affinities than CuTeQ. This suggests that these compounds have the potential as starting points for the production of new classes of antibiotics. Finally, a correlation of the in vitro activity with the DFT and molecular docking data has been done and discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: The coronavirus was declared a worldwide pandemic for the first time in December 2019. Although vaccination reduces the risk of severe illness and death, no vaccine is 100% foolproof. Recently, the COVID-19 primary protease has become a promising therapeutic target. During the preceding three years, many low molecular weight chemical libraries were tested for their potent antiviral potency against SARS-CoV-2. Many studies focused on organoselenium compounds due to their potential antiviral activities. Herein, new organoselenium-based Schiff bases were successfully synthesized and evaluated for their potential to inhibit the SARS-CoV-2 Mpro main protease, which is essential for virus replication. Since the first report of the organoselenium compound, ebselen, as a potent inhibitor of the SARS-CoV-2 Mpro main protease by Z. Jin et al. (Nature, 2020), different OSe analogs have been developed and evaluated for their anti-COVID-19 activities. Herein, organoselenium-clubbed Schiff bases were synthesized in good yields (up to 87%) and characterized using different spectroscopic techniques. Their geometries were studied by DFT using the B3LYP/6–311 (d, p) approach. Ten FDA-approved drugs targeting COVID-19 were used as model pharmacophores to interpret the binding requirements of COVID-19 inhibitors. The antiviral efficiency of the novel organoselenium compounds was assessed by molecular docking against the 6LU7 protein to investigate their possible interactions. Our results showed that the COVID-19 primary protease bound to organoselenium ligands with high binding energy scores ranging from −8.19 to −7.33 Kcal/mol for 4c and 4a to −6.10 to −6.20 Kcal/mol for 6b and 6a. Furthermore, the docking data showed that 4c and 4a are good Mpro inhibitors. Moreover, the drug-likeness studies, including Lipinski's rule and ADMET properties, were also assessed. Interestingly, the organoselenium candidates manifested solid pharmacokinetic qualities in the ADMET studies. Overall, the results demonstrated that the organoselenium-based Schiff bases might serve as possible drugs for the COVID-19 epidemic. [ABSTRACT FROM AUTHOR]

Herein, new Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes incorporating 4‐{[(2‐hydroxyphenyl)imino]methyl}phenyl 4‐methylbenzenesulfonate Schiff‐base ligand (HL) were designed, synthesized, and characterized. The structure of the new compounds was elucidated based on spectroscopic techniques (nuclear magnetic resonance [NMR], ultraviolet–visible [UV‐vis], infrared [IR], mass), magnetic, conductivity, thermal analysis (thermogravimetric analysis [TGA], differential thermal analysis [DTA]) measurements, in addition to complex stoichiometry determination using molar ratio and Job's methods. The new complexes showed an interesting structural variation: square‐planar (in the case of NiL), tetrahedral (in the case of CuL), and octahedral (in the case of FeL2, CoL2, and ZnL2). Furthermore, density functional theory (DFT) calculations were performed to obtain deep insights into the structural features, orbital interactions, and electronic chemical descriptors evaluation. Moreover, the anti‐inflammatory behavior of the titled compounds was in vitro investigated. Interestingly, the ZnL2 complex showed the highest activity, whereas the CuL complex showed the lowest activity compared with the other compounds. In order to ascertain the bioactivity of the present compounds, their efficacy was compared with previously reported compounds showing high activity. The anti‐inflammatory activity was supported by molecular docking analysis against cyclooxygenase‐2 (COX‐2) enzyme (PDB ID: 5IKT), which confirms the bioactivity behavior. The obtained results indicated that the titled compounds could be promising anti‐inflammatory candidates. [ABSTRACT FROM AUTHOR]

The present paper deals with synthesis new mononuclear 1:1:1 metal:ligand:co‐ligand complexes, FeLG, NiLG, and CuLG, where L = 1‐{(E)‐[(4‐methylphenyl)imino]methyl}‐2‐naphthol and G = Glycine. The synthesized complexes were characterized based on elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), ultraviolet–visible (UV–vis), mass spectra, molar conductance, magnetic susceptibility, and thermal analysis (TGA) in addition to stoichiometry determination via molar ratio method. The isolated metal complexes showed interesting geometry variation as tetrahedral for CuLG and octahedral for both FeLG and NiLG. The molecular structures of the titled compounds were optimized theoretically using density functional theory (DFT) approach, and the quantum chemical descriptors were calculated. The disk diffusion method was used to investigate the growth inhibition of the titled compounds aganist selected pathogenic bacterial and fungal strains. The metal complexes exhibited higher enhancement as antimicrobial candidates with lower minimum inhibitory concentration (MIC) than the free ligands, and in some cases, the complexes were closed to the standard species. Molecular docking investigation was carried out to ascertain the inhibitory action of the studied compounds against 1HNJ protein, the target enzyme for the antimicrobial agents. The results indicated that the FeLG has the highest binding affinity in comparison with other compounds. Thus, these molecules could be promising antimicrobial candidates. Furthermore, catalase mimicking activity of the complexes has been investigated. The data revealed that CuLG complex catalyzes the decomposition of hydrogen peroxide most effectively. Finally, the quantum chemical parameters of the titled complexes and other different compounds were correlated with their practical biological activity data in a trial to build a SAR model. [ABSTRACT FROM AUTHOR]

[Display omitted] • New Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), and Zn(II) complexes were synthesized and characterized. • 3D geometry was optimized using DFT approach. • In vitro antimicrobial activity was screened. • Molecular docking against 1HNJ protein was explored. • Drug-Likeness properties were investigated based on Lipinski rule. Herein, new Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes based on azocoumarin ligand, 2-[(E)-(2-oxo-2H-chromen-6-yl)diazenyl]-1-phenylbutane-1,3-dione (L), were synthesized and characterized via elemental analyses, IR, mass, UV–Vis spectra, magnetic susceptibility, conductivity measurements, and thermogravimetric analysis (TG). From IR spectra, it was elucidated that the azocoumarin ligand behaves as a neutral bi-dentate ligand and coordinates to the metal ions through the azo Nitrogen and carbonyl Oxygen. Number and position of the water molecules were investigated through thermal analysis. The molecular structures of the ligand (L) and its metal complexes were optimized theoretically using density functional theory (DFT) for various possible orientations of the H 2 O and Cl moieties around the metal-center, to find out the most reliable coordination modes. Moreover, the quantum chemical parameters were evaluated. The bioactivity of the ligand and its complexes were screened for their in vitro anti-bacterial and anti-fungal activity against series of pathogenic bacterial and fungal strains. The metal complexes possess high biological activity with low minimum inhibition concentration (MIC) against different organisms. In order to ascertain the bio-effect of the present compounds, their MIC was compared with previously reported MIC showing lower MIC values. Molecular docking was used to predict the binding efficiency between the prepared compounds and the receptor of E. coli (1HNJ), the target enzyme for the antimicrobial reagents. The protein-substrate interactions were investigated and the binding energies were calculated. The drug-likeness and ADMET prediction showed compliance with the Lipinski rule, and the compounds were found to have good absorption, distribution, metabolism, and excretion generally. The results were very encouraging, so we can say that these products are biologically active and can be used later in other applications towards drug development. [ABSTRACT FROM AUTHOR]

• New FeLphen, Colphen and Nilphen complexes were synthesized, characterized and theoretically investigated. • Optimization and vibrational study of the new compounds were performed using DFT approach. • The reactivity of the new compounds was evaluated using frontier orbitals studies. • In vitro evaluation of the synthesized compounds shows a good antimicrobial activity. • Molecular docking against 2VF5, 4FXQ, and 3cku was explored. • The experimental results are in good agreement with the theoretical investigation. Three new FeLphen, CoLphen and NiLphen hetero-ligand were synthesized, characterized and theoretically investigated. The new complexes were based on phenylalanine (Hphen) and 1-{(E)-[(4- methylphenyl) imino ]methyl}-2-naphthol Schiff-base (HL). The results showed interesting structural variety as octahedral for FeLphen ([F e (L)(phen)(C l)(H 2 O)]), CoLphen ([C o (L)(phen)(H 2 O) 2 ]) and tetrahedral for NiLphen ([N i (L)(phen)]). The molecular properties, geometric optimization, vibrational, frontier molecular orbital, and energy evaluation of the new complexes were characterized theoretically using density functional theory (DFT) approach. The calculations were performed to find out the most reliable cis /trans (Chloride and/or H 2 O) and the (HL/Hphen) orientations around the Fe(III)/Co(II) and Ni(II) center. The calculations revealed that trans-H 2 O/Cl-cis-N HL /N Hphen & cis-H 2 O/H 2 O-cis-N HL /N Hphen and cis-N HL /N Hphen were the most stable orientations for the FeLphen, CoLphen and NiLphen, respectively. Furthermore, the antibacterial and antifungal activity of the titled compounds was in vitro screened. The results showed that the metal complexes exhibited higher pathogenic effect than the free ligands against the selected microbes. Molecular docking investigation against 2VF5, 4FXQ, and 3cku, was carried out to provide deep insights into their role in inhibiting the growth of pathogenic microbes. Comparative analysis elucidated higher antibacterial and antifungal activity of the titled compounds compared with literature survey. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of new FePBZPHA, CoPBZPHA, and NiPBZPHA mixed-ligand complexes. • Stoichiometry determination confirming the 1:1:1 (M: PBZ: PHA) ratio; FT-IR spectra comparison elucidating intricate binding modes. • DFT calculations unveiling octahedral coordination geometries and enhanced electron affinity, electronegativity, and reactivity of metal complexes. • Biological evaluation showcasing significantly enhanced efficacy of metal complexes in antimicrobial, anti-inflammatory, and antioxidant activities, with FePBZPHA exhibiting the highest potency. • Molecular docking analysis highlighting potential therapeutic applications, with metal complexation enhancing binding affinity and interaction versatility. This study presents a thorough investigation into the synthesis, characterization, computational analysis, and biological evaluation of FePBZPHA, CoPBZPHA, and NiPBZPHA mixed-ligand complexes. They were synthesized in high yields via reactions between chloride salts of Iron, Cobalt, or Nickel with 2-(pyridin-2-yl)-1H-benzimidazole (PBZ) and Phenylalanine (PHA). They underwent extensive spectroscopic, elemental, conductivity, magnetic, and thermal analysis to confirm their formation. Molar conductivity measurements indicated their non-electrolytic nature, with UV–vis spectra revealing distinct absorption bands for PBZ and PHA ligands, shifting significantly upon metal ion coordination. Stoichiometry determination confirmed the 1:1:1 (M:PBZ:PHA) ratio, while FT-IR spectra comparison elucidated intricate binding modes, supported by mass spectra and elemental analysis. Thermal analysis revealed their thermal stability and decomposition pathways. DFT calculations unveiled octahedral coordination geometries and enhanced electron affinity, electronegativity, and reactivity of metal complexes. Biological evaluation showcased significantly enhanced efficacy of metal complexes in antimicrobial, anti-inflammatory, and antioxidant activities, with FePBZPHA exhibiting the highest potency. Molecular docking analysis highlighted their potential as therapeutic agents, with metal complexation enhancing binding affinity and interaction versatility. Overall, this study provides comprehensive insights into the synthesis, characterization, computational analysis, and biological evaluation of FePBZPHA, CoPBZPHA, and NiPBZPHA mixed-ligand complexes, suggesting promising applications in biomedicine and materials science. [ABSTRACT FROM AUTHOR]

• Preparation of some new mixed ligand complexes and their structural inspection • Geometry optimization for structural verification using DFT calculation • DNA interaction and biomedical evaluation of the prepared compounds • Molecular docking inspection for predicting of the biomedical evaluation The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N 2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with K f values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H 2 O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC 50 % are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC 50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three distinct FeHNANSA, NiHNANSA, and CuHNANSA have been prepared & characterized via a wide variety of analytical methods. • In vitro experiments were conducted to evaluate the antibacterial, antifungal, anti-inflammatory, and antioxidant properties of the prepared compounds. • The metal complexes have heightened biological efficacy as compared to the free HNANSA ligand. • The findings obtained from docking experiments indicate that these compounds may possess a physiological function. Three novel metal complexes of 2‑hydroxy-1-naphthaldehyde azine (HNANSA) with iron(III), nickel(II), and copper(II) have been synthesized and characterized. Various analytical methods, such as elemental analysis, infrared spectroscopy, mass spectrometry, ultraviolet–visible spectroscopy, conductivity, magnetic testing, and thermal analysis, have been used to determine the structural and physical properties of the HNANSA and its metal complexes. The results indicated that; the HNANSA acts as a monobasic bi-dentate NO donor ligand and that the metal complexes contain water molecules in different patterns. Also, density functional theory (DFT) calculations have been performed to confirm the molecular structures and to study the quantum chemical parameters of the HNANSA and its metal complexes. Furthermore, the antibacterial, antifungal, anti-inflammatory, and antioxidant activities of the HNANSA and its metal complexes have been in vitro evaluated. The findings revealed that; the metal complexes have higher bioactivty than the free HNANSA ligand. Furthermore, molecular docking analyses have been performed against 2VF5 (Escherichia coli), 3CKU (Aspergillus flavus), 5IKT (Human Cyclooxygenase-2), and 5IJT (human peroxiredoxin 2), to estimate the binding affinities and interactions of the HNANSA and its metal complexes with target proteins. The results suggest that the HNANSA and its metal complexes may have potential applications in the development of new therapeutic agents. [Display omitted] [ABSTRACT FROM AUTHOR]

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 H 2 AZD 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). [Display omitted] • Three FeAZD, NiAZD, and CuAZD complexes were synthesized and characterized. • The complexes had a more promising antimicrobial than the free ligand. • High ability of metal complexes to inhibit the growth of E. coli (PDB ID: 5iq9). • Positive results proposed various medicinal purposes for these compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] A new Schiff-base ligand, 4-[(4-oxo-4,5-dihydro-1,3-thiazol-2-yl)hydrazono]methylphenyl 4-methylbenzenesulfonate (L), and its Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized and characterized. Elemental analysis, NMR spectroscopy, mass spectra, FT-IR analysis, molar conductivity, magnetic susceptibility tests and electronic spectra (UV-vis.) were all used to describe the ligand and its metal complexes. The complexes of Ni(II) and Zn(II) were found to have a tetrahedral structure, whereas those of Fe(III), Co(II) and Cu(II) exhibited an octahedral structure. The geometry of the ligand and its metal complexes was investigated by density functional theory (DFT) calculations at the B3LYP/6-311G(d, p) and LanL2dz levels of theory, respectively. To round out the picture, we evaluated not only the overall energy but also the HOMO and LUMO molecular orbitals and the molecular electrostatic potential (MEP). The synthetic analogues were tested for their in vitro antibacterial and antifungal efficacy against various pathogens using the disc diffusion method. The research shows that the metal complexes are more effective against these diseases than the free ligand. In addition, the DPPH method was used to measure the antioxidant activity in vitro. The antioxidant activity of each complex was higher than that of its free corresponding ligand. Molecular docking was carried out to determine the interactions between the complexes and the probable binding sites of Human Peroxiredoxin 2 Oxidized (PDB ID: 5IJT) and Escherichia coli (PDB ID: 3t88) receptors. [ABSTRACT FROM AUTHOR]

• Novel VO(II), Mn(II), Fe(III), Zn(II), and Ag(I)-benzenesulfonamide complexes have been synthesized. • The metal complexes have enhanced biological activity against their target microorganisms compared to the unbound ligand. • In vitro research was also conducted on the anti-inflammatory effects of the aforementioned substances. • The prepared compounds have physiological effects and might have broad use in the pharmaceutical industry. In this work, we synthesized and studied novel VO(II), Mn(II), Fe(III), Zn(II), and Ag(I) − 4-((2-hydroxy-1-naphthyl)azo) benzenesulfonamide complexes. Characterization techniques such as thermogravimetry (T.G.A), magnetic susceptibility testing, electrical conductivity studies, infrared spectroscopy, and mass spectroscopy all played crucial roles. Metal ions are coordinated by the azo Nitrogen (N N) and the hydroxyl Oxygen (–OH), as seen by the infrared spectra (IR). Our investigation of water's distribution and thermal behavior, in addition to its overall number, was made possible by techniques from thermogravimetry (T.G.A). The theoretical optimization of ligand (HL) and its metal complexes' molecular structures was accomplished by the use of density functional theory (DFT). Other quantum chemical properties might potentially be derived by using the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energy levels. In vitro testing was performed on both the ligand and its complexes to see whether or not they were capable of inhibiting the growth of harmful bacteria and fungi. The metal complexes have enhanced biological activity against the target microorganisms compared to the unbound ligand. In vitro research was also conducted on the anti-inflammatory effects of the aforementioned substances. Surprisingly, the AgL complex was the least active of the compounds tested, while the FeL complex was the most active. Based on molecular docking studies, we hypothesized that the synthesized compounds would bind to the cyclooxygenase-2 (COX-2) enzyme (Protein Data Base (PDB) ID: 5IKT) and the E. coli DNA gyrase B receptor (PDB ID: 1KNZ). Binding energies were calculated after studying protein-substrate interactions in depth. The molecular docking indications are that these compounds have physiological effects and might have broad use in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

New Ni (II) ternary chelates; based on 2-hydroxy-1-naphthaldehyde Schiff-base ligand with various N-heterocyclic co-ligands, were synthesized and characterized. Structural analysis were performed to estimate the chelates stability based on the cis- and trans- orientation around the Ni(II)-center using density functional theory (DFT) calculations. Moreover, selected quantum chemical descriptors had been computed using frontier molecular orbitals to evaluate the reactivity based on the electronic structural analysis. Pharmaceutical potential of the subject molecules have been estimated by screening the most important drug-likeness parameters. In silico investigation revealed that the target compounds could be potential bioactive drug-like molecules. Mixed-ligand effect on antimicrobial activity was in-vitro screened against pathogenic bacteria; E. coli (G−), and B. cereus (G+), as well as A. fumigatus fungi. Interestingly, presence of co-ligand in the ternary Ni (II) chelates led to higher enhancement in the antimicrobial behavior comparing with its binary one. Finally, both theoretical and experimental data were combined for generating a structure activity relationship (SAR) model that might be used for the developing of new metal chelates as antimicrobial agents. • Synthesis and characterization of new Ni(II) ternary complexes. • Electronic structure and chemical descriptors analysis based on DFT calculations. • Evaluation of the pharmacokinetics and drug-likeness properties. • In-vitro screening of the antimicrobial activity of the prepared titled compounds. • Deriving a SAR model between actual activity and calculated chemical descriptors. [ABSTRACT FROM AUTHOR]