A novel semicarbazone NO 2 ligand, H 2 L, was synthesized. The ligand reacted with several metal ions such as Cu(II), Ni(II), Co(II), Fe(III), Cr(III), and Mn(II) in a molar ratio 1:1 (M:L). The H 2 L ligand and its metal complexes were characterized by electronic, infrared, mass, nuclear magnetic resonance, electron spin resonance spectra, as well as elemental analysis, thermal analysis, molar conductance, and magnetic susceptibility measurements. The Coats-Redfern equations were used to calculate the kinetic parameters (E a , A, ΔH, ΔS, and ΔG) of the thermal decomposition stages. The H 2 L ligand acts as dianionic NO 2 tridentate in all complexes and coordinates through enolate oxygen, azomethine nitrogen, and deprotonated OH group. The geometrical arrangements in all metal complexes were octahedral geometries. Based on density functional theory (DFT) level implemented in the Gaussian 09 program at B3LYP/6-311G(d,p) level, the molecular structural parameters of the ligand and its metal complexes were calculated, and the theoretical data were connected with the experimental results. The antimicrobial activity of the current compounds was examined against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans), and fungus (Aspergillus fumigatus). The antitumor activity of the ligand and its metal complexes was investigated against HepG2 cell line, which revealed promising IC 50 values comparable with that of Cis-platin. All synthesized compounds were also subjected to molecular docking studies to investigate their binding pattern and affinity for the VEGFR-2 active site and correlated with antitumor data.

A versatile, efficient, clean, and facile method was used for the synthesis of pyrano[2,3‐d]pyrimidine derivatives by the one‐pot three‐component condensation reaction of thiobarbituric acid and malononitrile with p‐chlorobenzaldehyde, using Fe3O4 or ZnO or Mn3O4 as nanostructure catalysts. The catalyst could be easily recovered using an external magnet and reused for six cycles with almost a consistent activity. A series of polyheterocyclic compounds containing five and/or six rings fused with each other was designed. The anti‐inflammatory activities for some of the newly synthesized compounds were evaluated. All the synthesized compounds were characterized on the basis of their elemental analyses and spectral data.

Novel candidates of 3-(4-(thiophen-2-yl)-pyridin/pyran/pyrimidin/pyrazol-2-yl)-1H-indole derivatives (2–12) were designed by pairing the pyridine/pyrane/pyrimidine/pyrazole heterocycles with indole and thiophene to investigate their potential activities as (2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) inhibitors. The purpose of these derivatives’ modification is to create high-efficiency antioxidants, especially against ABTS, as a result of the efficiency of this set of key heterocycles in the inhibition of ROS. Herein, 2D QSAR modeling was performed to recommend the most promising members for further in vitro investigations. Furthermore, the pharmacological assay for antioxidant activity evaluation of the yielded indole-based heterocycles was tested against ABTS (2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid); by utilizing ascorbic acid as the standard. Candidate 10 showed higher antioxidant activity (IC50 = 28.23 μg/mL) than ascorbic acid itself which achieved (IC50 = 30.03 μg/mL). Moreover, molecular docking studies were performed for the newly designed and synthesized drug candidates to propose their mechanism of action as promising cytochrome c peroxidase inhibitors compared to ascorbic acid as a reference standard. Our findings could be promising in the medicinal chemistry scope for further optimization of the newly designed and synthesized compounds regarding the introduced structure-activity relationship study (SAR) in order to get a superior antioxidant lead compound in the near future.

No abstract

No abstract

On our way to discovering and developing compounds that have an antioxidant impact compared to ascorbic acid and other biological activities, we designed, synthesized, and evaluated a new series of heterocyclic moieties drugs (1–11) as antioxidants and antimicrobial agents. As starting moieties, these new candidates were derived from two promising heterocyclic compounds, imidazoldin-4-one and thiazol-4-one. Firstly, diphenylimidazol 1 was obtained because of the cyclo condensation one-pot ternary reaction of urea, aniline, and chloroacetic acid under thermal conditions. Out of this starting compound, we could design and create new vital rings such as purine and triazine as in compounds 5 and 6, respectively. Secondly, the start thiazole derivative 7 was obtained from the intermolecular cyclization of thiourea, chloroacetic acid, p-nitobezaldehyde in the presence of sodium acetate. We synthesized various derivatives from this second starting compound 7 by being subjected to different reagents such as aniline, phenylenediamine, phenylhydrazine, and barbituric acid to yield 8, 9, 10, and 11, respectively. Using ascorbic acid as the standard compound, the pharmacological testing for antioxidant activity assessment of the produced derivatives was evaluated against ABTS (2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid). Candidate 6 exhibited the best activity as an antioxidant agent compared to ascorbic acid as a reference compound. Moreover, all compounds were evaluated as antimicrobial agents against a series of bacteria and fungi. Among all synthesized compounds, compound 6 achieved high efficiency against two types of fungi and four kinds of bacteria, as Clotrimazole and Ampicillin were used as the reference agents, respectively. All chemical structures of the novel synthesized candidates were unequivocally elucidated and confirmed utilizing spectroscopical and elemental investigations.

No abstract

New Zn(II), Cd(II), VO(IV), and UO2(VI) solvatochromic complexes derived from 6‐ethyl‐4‐hydroxy‐2,5‐dioxo‐5,6‐dihydro‐2H‐pyrano[3,2‐c]quinoline‐3‐carboxaldehyde‐semicarbazone ligand (H2L) were synthesized and established by elemental analyses, spectral (IR, UV, NMR, mass spectra), molar conductivity measurements, magnetic susceptibility, and thermal gravimetric analysis (TGA). The ligand coordinates with metal ions through ONO chelating sites, forming an octahedral geometry arrangement, except UO2(VI) that showed pentagonal bipyramidal geometry. Using Coats–Redfern methodology, the kinetic parameters (Ea, A, ΔH, ΔS, and ΔG) of the thermal decomposition steps were calculated and discussed. The complexes showed solvatochromic behavior that used to estimate the ground and excited state dipole moments. Optimization and structural parameters were carried out by density function theory (DFT) at B3LYP/GENECP method at 6‐311G(d,p) basis set for C, H, N, and O atoms and SDD (Stuttgart/Dresden) basis set for the metal atoms and interrelated with the experimental results. The complexes were tested for antimicrobial efficiency against Gram‐positive bacteria, Gram‐negative bacteria, yeast, and fungi. Also, antitumor activity was investigated against HepG‐2 cell line. Finally, the new synthesized complexes upon subjecting to molecular docking and distinguishable results showed outstanding inhibition results of VEGFR‐2 via achieving a high stabilization level inside the largest pocket of 1YWN protein.