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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. [ABSTRACT FROM AUTHOR]

Some novel imine metal chelates with Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ cations were produced from 2-acetylferrocene and 3-aminophenol. The new acetylferrocene azomethine ligand ((Z)-cyclopenta-1,3-dien-1-yl(2-(1-((3-hydroxyphenyl)imino)ethyl)cyclopenta-2,4-dien-1-yl)iron) and its metal ion chelates were constructed and elucidated using FT-IR, UV/Vis, 1HNMR, DTA/TGA, CHNClM studies, mass spectrometry and SEM analysis. According to the TGA/DTG investigation, the ferrocene moiety spontaneously disintegrates to liberate FeO. The morphology of the free acetylferrocene azomethine via SEM analysis was net-shaped with a size of 64.73 nm, which differed in Cd(II) complex to be a spongy shape with a size of 42.43 nm. The quantum chemical features of the azomethine ligand (HL) were computed, and its electronic and molecular structure was refined theoretically. The investigated acetylferrocene imine ligand behaves as bidinetate ligand towards the cations under study to form octahedral geometries in case of all complexes except in case of Zn2+ is tetrahedral. Various microorganisms were used to investigate the anti-pathogenic effects of the free acetylferrocene azomethine ligand and its metal chelates. Moreover, the prepared ligand and its metal complexes were tested for anticancer activity utilizing four different concentrations against the human breast cancer cell line (MCF7) and the normal melanocyte cell line (HBF4). Furthermore, the binding of 3-aminophenol, 2-acetylferrocene, HL, Mn2+, Cu2+, and Cd2+ metal chelates to the receptor of breast cancer mutant oxidoreductase was discovered using molecular docking (PDB ID: 3HB5). [ABSTRACT FROM AUTHOR]

The newly synthesized organometallic acetyl ferrocene imine ligand (HL) was obtained by the direct combination of 2-acetyl ferrocene with 2-aminothiophenol. The electronic and molecular structure of acetyl ferrocene imine ligand (HL) was refined theoretically and the chemical quantum factors were computed. Complexes of the acetyl ferrocene imine ligand with metal(II)/(III) ions (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)) were fabricated. They were inspected by thermal (DTG/TG), spectroscopic techniques (FT-IR, 1H NMR, mass, UV–Vis), molar conductivity, and CHNClM to explicate their structures. Studies using scanning electron microscope (SEM) were conducted on the free acetyl ferrocene imine ligand and its Cd(II) chelate to confirm their nano-structure. To collect an idea about the effect of metal ions on anti-pathogenic properties upon chelation, the newly synthesized acetyl ferrocene imine ligand and some of its metal chelates were tested against a variety of microorganisms, including Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Aspergillus fumigatus, and Candida albicans. The ligand and its metal chelate were tested for cytotoxic activity in human cancer (MCF-7 cell viability) and human melanocyte cell line HBF4. It was discovered that the Cd(II) chelate had the lowest IC50 of the three and thus had the prior activity. Molecular docking was utilized to investigate the interaction of acetyl ferrocene imine ligand (HL) with the receptors of the vascular endothelial growth factor receptor VEGFR (PDB ID: 1Y6a), human Topo IIA-bound G-segment DNA crystal structure (PDB ID: 2RGR), and Escherichia coli crystal structure (PDB ID: 3T88). [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of some new tripodal metal chelates and their structural elucidation. • Geometry optimization for structural confirmation. • Biomedical applications against microbes and carcinoma cell lines. • Docking approach for biomedical applications inspection. Direct condensation of 2-acetylferrocene with tris(2-aminoethyl)amine resulted in a novel tripodal imine ligand (L). Treatment of the metals' chlorides (Fe3+, Cr3+, Co2+, Ni2+, Cu2+, Mn2+, Cd2+, and Zn2+) with equimolar ratio of the tripodal imine ligand led to cleaned production of the equivalent mononuclear complexes. They are well characterized by different physicochemical analyzing tools such as CHN, FT-IR as well as electronic spectroscopy, mass spectrometry and TGA analyses. Furthermore, scanning electron microscope (SEM) study for the tested ligand as well as Cd(II) chelate proved that it was nanosized. The stoichiometry of the prepared metal chelates in solution confirm M:L is 1:1 ratio. The DFT calculations demonstrated that all metal complexes possess octahedral geometry in accordance with the experimentally deduced geometry. The MEP surface indicated the reactive regions of the compounds for electrophilic and nucleophilic attack. HOMO-LUMO analysis implies charge transfer interaction during complex formation. Quantum chemical reactivity parameters showed that the complexes are stable and the decomposition process into constituent elements does not occur. Morover, anti-pathogenic and anticancer activities were studied against different bacterial, fungal strains and selected cancer cell lines. The metal chelates show potent anti-microbial and anti-cancer activity than its tripodal imine ligand. Furthermore, MOE-docking of the title ligand, Cu(II) as well as Cd(II) chelate was studied with crystal structure of the antimalarial drug Amediaquine (3AOU), colon cancer antigen10 (2HQ6), breast cancer (3HB5) and gastrointestinal cancer (4IJO). [ABSTRACT FROM AUTHOR]

• Synthesis of Schiff base derived from ofloxacin drug and 2-aminophenol. • Synthesis of 3d series metal complexes of the Schiff base ligand. • Characterization using different spectroscopic tools. • Theoretical studies (DFT and molecular docking). • Different applications (anticorrosion, antimicrobial and antioxidant). A new tridentate Schiff base ligand derived from ofloxacin (oflo) with 2-aminophenol was synthesized and a series of d-transition metal complexes were prepared. The ligand and its metal complexes were investigated using elemental, spectral, and thermal studies. The molecular and electronic structure of the free ligand and its Zn(II) complex were refined theoretically, and the chemical quantum parameters were computed. SEM studies were conducted on the free ligand and its Ni(II) chelate to confirm their nanostructure. The anti-corrosive performance of HL for mild steel (MS) was employed using electrochemical frequency modulation (EFM), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) and showed a significant efficiency as anticorrosion agent (89.71%). Molecular docking studies were carried out between the ligand and its [Zn(HL)(H 2 O)Cl 2 ] complex with active sites of 3T88, 3Q8U, and 3Q7K receptors and the complex showed the strongest binding with 3T88 receptor (-31.9 kcal mol−1). The antioxidant activity of the free ligand and its metal chelates had been carried out using the standard DPPH method and the free ligand showed the highest antioxidant activity (IC 50 = 10.52 µg/mL). The in vitro antibacterial activity showed that all prepared compounds were biologically active and Fe(III) complex has the highest inhibiting activity against Proteus Vulgaris Gram-negative bacteria. [Display omitted] [ABSTRACT FROM AUTHOR]

An azo derivative was synthesized by coupling diazotized 2,6‐diaminopyridine with p‐dimethyl amino benzaldehyde and this new ligand formed a series of metal complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) salts. These complexes were characterized on the basis of elemental analyses, molar conductance, infrared spectroscopy, UV–Vis, 1H NMR, mass spectrometry, electronic spectra, magnetic susceptibility and ESR spectral studies, conductivity measurements, thermogravimetric analyses (TG‐DTG). The molecular and electronic structure of the azo ligand was optimized theoretically and the quantum chemical parameters were calculated. The ligand and its metal complexes were subjected to X‐ray powder diffraction study. The thermal stability of the ligand and its metal complexes was examined by thermogravimetry. The ligand and its complexes were tested for their in vitro antimicrobial activity, some of the complexes showed good antimicrobial activities against some selected bacterial and fungal strains. Anticancer activity of the ligand and its metal complexes are evaluated against human cancer (MCF‐7 cells viability). Molecular docking was used to predict the binding between azo ligand and the receptors of nucleoside diphosphate kinase of Staphylococcus aureus (3Q8U) and (3HB5) which is breast cancer mutant oxidoreductase. The docking study provided useful structural information for inhibition studies. [ABSTRACT FROM AUTHOR]

• Novel PtII/PdII metal complexes of ferrocenyl based Schiff bases. • Different spectroscopic tools for characterization. • Anticancer and antibacterial activities studies show good recommendations for further trials. • Molecular docking studies also confirm experimental data. Four new Pt(II)/Pd(II) complexes were prepared, [Pt(L1)(H 2 O) 2 ]Cl 2 ·3H 2 O (1) , [Pd(L1)(H 2 O) 2 ]Cl 2 ·4H 2 O (2) , [Pt(L2)(H 2 O)Cl]Cl·5H 2 O (3) and [Pd(L2)(H 2 O)Cl]Cl·3H 2 O (4). Ligands derived from 2-acetylferrocene with 4‐nitro‐1,2‐phenylenediamine (L1) and with 3,4-diaminopyridine (L2) were synthesized. Structures of complexes were confirmed based on different spectroscopic techniques. The results showed that synthesized complexes offered 1:1 metal‐ligand ratios. All complexes were electrolytes and had square planar structure. IR spectra designated that Schiff bases were coordinated to Pt/Pd ions in a bidentate manner, N,N donor sites of azomethine-N and amino-N. Thermal behavior of these chelates indicated that hydrated complexes lost water molecules of hydration in the first step and was immediately followed by decomposition of the ligand molecules in the subsequent steps. Investigation of bioactivity for complexes and ligands exposed their moderate antibacterial activities against four Gram positive bacteria (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Streptococcus faecalis) and four Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Neisseria gonorrhoeae and S. typhimrium). In cytotoxicity studies with MCF-7 cell line, all compounds exhibited good cytotoxic properties, in which complex (4) had the lowest IC 50 value (11.0 µg/mL). Finally, the antibacterial and cytotoxicity studies of prepared compounds were confirmed by comparing experimental results with theoretical ones from molecular docking studies with three different protein receptors (3HB5, 3Q8U and 3T88). [Display omitted] [ABSTRACT FROM AUTHOR]

A new azo dye with N3O2 donor set of atoms has been synthesized via of 2,6-diaminopyridine with p-methoxybenzaldehyde. The molecular and electronic structure of the azo dye ligand (L) was optimized theoretically and the quantum chemical parameters were calculated. Molecular docking was used to predict the binding between L and the receptors of breast cancer mutant 3hb5-oxidoreductase, crystal structure of Escherichia coli (3 T88) and crystal structure of Staphylococcus aureus (3q8u). The newly synthesized L was used for complex formation with Cr(III), Mn(II), Fe(III), Co.(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions. The nature of bonding and the stoichiometry of L and its mononuclear complexes were deduced from elemental analyses, spectroscopic, magnetic susceptibility, molar conductance, and conductivity measurements, thermogravimetric analyses and powder X-ray diffraction. Elemental analysis data show that the complexes have composition of ML type with an octahedral geometry for all the complexes. The activation thermodynamic parameters were calculated. The prepared azo dye and its metal complexes were tested against various Gram-positive and Gram-negative bacteria and a fungus. Most complexes exhibit antibacterial and antifungal activities against these organisms. Anticancer evaluation studies against standard breast cancer cell line were performed using various concentrations. The activity index was calculated. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• Newly synthesized lanthanides complexes of ferrocene-based Schiff base. • These metal complexes were characterized using different spectroscopic, elemental analysis and thermal analysis. • Biological and anticancer activities were tested and promising activities. • Molecular docking was studied on two different proteins receptors of breast cancer mutant oxidoreductase (3HB5) and colon cancer isomerase (2HQ6). • Yb(III) complex can be used as breast and colon cancer drugs. Amino acids are the fundamental building blocks of proteins and are involved in all major biological activities. Schiff bases being active biological moieties and possessing diverse pharmacological activities. Herein, the previously synthesized Schiff base ligand (HL) underwent metal complex formation, to get their La(III), Er(III) and Yb(III) metal complexes. These metal complexes were characterized using different spectroscopic tools as elemental analysis, FT-IR, mass, UV-Vis spectra, thermal analysis (TG) and scanning electron microscope (SEM). According to the elemental analysis data, the complexes were found to have octahedral geometry with the formula [M(L)(H 2 O) 2 Cl]Cl.nH 2 O (M = La(III), n = 2; Er(III), n = 4 and Yb(III), n = 1). The ligand binds to the metal ions with mononegative tridentate mode through the carboxylic oxygen, imidazole nitrogen and azomethine nitrogen as deduced from the IR spectra. The complexes decomposed within two or three steps from room temperature to 1000 °C as elucidated from TG. Also, biological and anticancer activities were tested and promising activities. Molecular docking was studied on two different proteins, the receptor of breast cancer mutant oxidoreductase (3HB5) and the receptor of colon cancer isomerase (2HQ6). The results recommended that Yb(III) complex can be used as breast and colon cancer drugs. [Display omitted] [ABSTRACT FROM AUTHOR]

Levofloxacin and 4‐aminoantipyrine undergo a condensation process to synthesize a novel Schiff base ligand (L). Metal complexes containing Co(II), Cu(II), Cd(II), Mn(II), Zn(II), Cr(III), Ni(II), and Fe(III) metal ions are prepared using this Schiff base ligand. The new ligand and its complexes are characterized by elemental analyses, Fourier transform infrared, mass spectrometry, ultraviolet–visible, magnetic moment, 1H‐NMR, molar conductivity, and powder X‐ray diffraction, and further thermogravimetric analysis (TG, DTA) verifies their thermal stability. The metal to ligand ratio is 1:1, according to the analytical results. Spectroscopic methods reveal that metal complexes are expected to have an octahedral geometry and demonstrate a neutral tridentate ligand behavior. It also becomes apparent from the molar conductivity values that all metal complexes are electrolytic in nature except zinc(II) and cadmium(II) complexes which are non‐electrolytes. Moreover, the bioactivity of the compounds are investigated. The antibacterial activity is investigated in relation to various Gram‐positive and Gram‐negative bacteria. The results give good indication for higher activity of the prepared compounds than the standard antibiotic drug. Also, the antioxidant activity of the newly prepared ligand and its complexes has been investigated via 2,2‐diphenyl‐1‐picrylhydrazyle (DPPH) free radical scavenging assay. The findings show that Schiff base complexes exhibit good antioxidant activity. Finally, theoretical density functional theory using density functional theory/B3LYP method and molecular docking studies with two receptors of 3T88 and 3Q8U are calculated for the investigated compounds. [ABSTRACT FROM AUTHOR]

A novel bidentate Schiff base ligand (L) and some d‐transition metal chelates (Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II), Zn (II) and Cd (II)) were synthesized and characterized using various physicochemical and spectroscopic techniques like elemental analysis, IR, mass, UV–visible and thermal analysis. The spectroscopic data suggested that the parent Schiff base ligand coordinated to the metal ions through both imine nitrogen atoms. The molecular and electronic structure of the free ligand was optimized theoretically, and the quantum chemical parameters were calculated. The molecular structure can be used to investigate the coordination sites and the total charge density around each atom. The free ligand and its complexes were screened for their antimicrobial activities for various pathogenic bacteria and fungi. The anticancer activities of the free ligand, Cr (III), Mn (II) and Fe (III) complexes were screened against MCF‐7 cell line and found that Mn (II) complex has the lowest IC50 (15.90 μg/ml). Molecular docking was used to predict the binding between the free ligand with receptor of mutant human androgen (ARccr) derived from androgen‐independent prostate cancer (1GS4), crystal structure of yeast‐specific serine/threonine protein phosphatase (ppz1) of Candida Albicans (5JPE) and crystal structure of renal tumor suppressor protein, folliculin (3 V42) and to identify the binding mode and the crucial functional groups interacting with the three proteins. Highlights: Novel ferrocene‐based Schiff base ligand was prepared and its metal complexes.Many Physicochemical tools are used for characterization.The ligand is optimized theoretically using DFT calculations.Biological activity, anticancer activity and molecular docking studies are evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] Inspired by the antitubercular activity of isoniazid (INH) and 5-bromoisatin, isatin–INH hybrid (WF-208) has been synthesized as a potent agent against multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of M. tuberculosis. In silico molecular docking studies indicated that DprE1, a critical enzyme in the synthesis of M. tuberculosis cell wall, is a potential enzymatic target for WF-208. The synthesized WF-208 was incorporated into a nanoparticulate system to enhance stability of the compound and to sustain its antimicrobial effect. Nanosized spherical niosomes (hydrodynamic diameter of ca. 500–600 nm) could accommodate WF-208 at a high encapsulation efficiency of 74.2%, and could impart superior stability to the compound in simulated gastric conditions. Interestingly, WF-208 had minimal inhibitory concentrations (MICs) of 7.8 and 31.3 µg/mL against MDR and XDR M. tuberculosis , respectively, whereas INH failed to demonstrate bacterial growth inhibition at the range of the tested concentrations. WF-208-loaded niosomes exhibited a 4-fold increase in the anti-mycobacterial activity as compared to the free compound (MIC of 1.9 vs. 7.8 µg/mL) against H37Rv M. tuberculosis , after three weeks of incubation with WF-208-loaded niosomes. Incorporation of the compound into nanosized vesicles allowed for a further increase in stability, potency and sustainability of the anti-mycobacterial activity, thus, providing a promising strategy for management of tuberculosis. [ABSTRACT FROM AUTHOR]