Şamil Işık

Synthesis, anticonvulsant and antimicrobial activities of some new 2-acetylnaphthalene derivatives.

In this study, as a continuation of our research for new (arylalkyl)imidazole anticonvulsant compounds, the design, synthesis and anticonvulsant/antimicrobial activity evaluation of a series of 2-acetylnaphthalene derivatives have been described. Molecular design of the compounds has been based on the modification of nafimidone [1-(2-naphthyl)-2-(imidazol-1-yl)ethanone], which is a representative of the (arylalkyl)imidazole anticonvulsant compounds as well as its active metabolite, nafimidone alcohol (3, 4). In general, these compounds were variously substituted at the alkyl chain between naphthalene and imidazole rings and subjected to some other modifications to evaluate additional structure-activity relationships. The anticonvulsant activity profile of those compounds was determined by maximal electroshock seizure (MES) and subcutaneous metrazol (scM) seizure tests, whereas their neurotoxicity was examined using rotarod test. All the ester derivatives of nafimidone alcohol (5a-h), which were designed as prodrugs, showed anticonvulsant activity against MES-induced seizure model. Four of the most active compounds were chosen for further anticonvulsant evaluations. Quantification of anticonvulsant protection was calculated via the ip route (ED(50) and TD(50)) for the most active candidate (5d). Observed protection in the MES model was 38.46mgkg(-1) and 123.83mgkg(-1) in mice and 20.44mgkg(-1), 56.36mgkg(-1) in rats, respectively. Most of the compounds with imidazole ring also showed antibacterial and/or antifungal activities to a certain extent in addition to their anticonvulsant activity.

An experimental and DFT computational study on 4-(3-(1H-imidazol-1-yl)propyl)-5-methyl-2H-1,2,4-triazol-3(4H)-one monohydrate

The triazole compound 4-(3-(1H-imidazol-1-yl)propyl)-5-methyl-2H-1,2,4-triazol-3(4H)-one monohydrate has been synthesised and characterised by 1H-NMR, 13C-NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the triclinic space group with a = 9.0366(7) Å, b = 11.5690(8) Å, c = 12.0571(9) Å, α = 110.733(6)°, β = 94.172(6)°, γ = 98.085(6)° and Z = 4. In addition to the molecular geometry from X-ray determination, the molecular geometry, vibrational frequencies and gauge, including atomic orbital (GIAO) 1H- and 13C-NMR chemical shift values of the title compound in the ground state, were calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The calculated results show that the optimised geometries can well reproduce the crystal structure, and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. The energetic behaviour of the title compound in solvent media was examined using the B3LYP method with the 6-31G(d) basis set by applying the Onsager model. The total energy of the title compound decreases with increasing polarity of the solvent. The predicted nonlinear optical properties of the title compound are greater than those of urea. In addition, DFT calculations of the molecular electrostatic potentials, frontier molecular orbitals and thermodynamic properties of the title compound were carried out at the B3LYP/6-31G(d) level of theory.

Theoretical modeling and experimental studies on N-n-Decyl-2-oxo-5-nitro-1-benzylidene-methylamine

The Schiff base compound, N-n-Decyl-2-oxo-5-nitro-1-benzylidene-methylamine, has been -synthesized and characterized by IR, electronic spectroscopy, and X-ray single-crystal determination. Molecular geometry from X-ray experiment of the title compound in the ground state have been compared using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. Calculated results show that density functional theory (DFT) at B3LYP/6-31G(d) level can well reproduce the structure of the title compound. To investigate the solvent effect for the atomic charge distributions of the title compound, self-consistent reaction field theory with Onsager reaction field model was used. In addition, DFT calculations of the title compound, molecular electrostatic potential and thermodynamic properties were performed at B3LYP/6-31G(d) level of theory.

Synthesis and molecular modeling of some novel hexahydroindazole derivatives as potent monoamine oxidase inhibitors.

A novel series of 2-thiocarbamoyl-2,3,4,5,6,7-hexahydro-1H-indazole and 2-substituted thiocarbamoyl-3,3a,4,5,6,7-hexahydro-2H-indazoles derivatives were synthesized and investigated for the ability to inhibit the activity of the A and B isoforms of monoamine oxidase (MAO). The target molecules were identified on the basis of satisfactory analytical and spectra data (IR, (1)H NMR, (13)C NMR, (2)D NMR, DEPT, EI-MASS techniques and elemental analysis). Synthesized compounds showed high activity against both the MAO-A (compounds 1d, 1e, 2c, 2d, 2e) and the MAO-B (compounds 1a, 1b, 1c, 2a, 2b) isoforms. In the discussion of the results, the influence of the structure on the biological activity of the prepared compounds was delineated. It was suggested that non-substituted and N-methyl/ethyl bearing compounds (except 2c) increased the inhibitory effect and selectivity toward MAO-B. The rest of the compounds, carrying N-allyl and N-phenyl, appeared to select the MAO-A isoform. The inhibition profile was found to be competitive and reversible for all compounds. A series of experimentally tested (1a-2e) compounds was docked computationally to the active site of the MAO-A and MAO-B isoenzyme. The autodock 4.01 program was employed to perform automated molecular docking. In order to see the detailed interactions of the docked poses of the model inhibitors compounds 1a, 1d, 1e and 2e were chosen because of their ability to reversibly inhibit the MAO-B and MAO-A and the availability of experimental inhibition data. The differences in the intermolecular hydrophobic and H-bonding of ligands to the active site of each MAO isoform were correlated to their biological data. Observation of the docked positions of these ligands revealed interactions with many residues previously reported to have an effect on the inhibition of the enzyme. Excellent to good correlations between the calculated and experimental K(i) values were obtained. In the docking of the MAO-A complex, the trans configuration of compound 1e made various very close interactions with the residues lining the active site cavity these interactions were much better than those of the other compounds tested in this study. This tight binding observation may be responsible for the nanomolar inhibition of form of MAOA. However, it binds slightly weaker (experimental K(i)=1.23 microM) to MAO-B than to MAO-A (experimental K(i)=4.22 nM).

4-(2,3-Dihydroxybenzyl­ideneamino)-3-methyl-1H-1,2,4-triazol-5(4H)-one

All the non-H atoms of the title compound, C10H10N4O3, are almost coplanar, the maximum deviation from planarity being 0.065 (3) Å. The dihedral angle between the aromatic rings is 1.66 (6)°. The molecule adopts the enol–imine tautomeric form with an intramolecular hydrogen-bonding interaction between the Schiff base N atom and the hydroxy group. In the crystal, intermolecular N—H⋯O and O—H⋯O hydrogen bonds link the molecules into a three-dimensional network.

Ethyl 4-(3-ethyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-4-yl)benzoate

In the title compound, C13H15N3O3, the dihedral angle between the two aromatic ring is 51.06 (1)°. In the crystal, molecules are connected by pairs of N—H⋯O hydrogen bonds into centrosymmetric dimers.

2-Hydr-oxy-5-nitro-benzaldehyde.

The title compound, C7H5NO4, is essentially planar, with a maximum deviation from the mean plane of 0.0116 (11) Å for the hydroxy O atom. The molecular and crystal structure are stabilized by intra- and intermolecular interactions. An intramolecular O—H⋯O hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The C—H⋯O interactions result in the formation of C(5) chains and R 2 2(8) rings forming an approximately planar network parallel to (10). These planes are interconnected through π–π interactions [centroid–centroid distance 3.582 (2) Å].

2,5-Dihexyl-3,6-diphenyl-pyrrolo-[3,4-c]pyrrole-1,4(2H,5H)-dione.

The asymmetric unit of the title compound, C30H36N2O2, contains one half-molecule, the other half being generated by a crystallographic inversion centre. The crystal structure is devoid of any classical hydrogen bonds however, non-classical C—H⋯O interactions link the molecules into chains propagating in [001] and a C—H⋯π interaction leads to the formation of a two-dimensional network in (011).

Structural properties of trans-cyclohexane-1,2-diamine complexes of copper(II) and zinc(II) acesulfamates

The title compounds, trans-bis(trans-cyclohexane-1,2-diamine)bis(6-methyl-2,2,4-trioxo-3,4-dihydro-1,2,3-oxathiazin-3-ido)copper(II), [Cu(C(4)H(4)NO(4)S)(2)(C(6)H(14)N(2))(2)], (I), and trans-diaquabis(cyclohexane-1,2-diamine)zinc(II) 6-methyl-2,2,4-trioxo-3,4-dihydro-1,2,3-oxathiazin-3-ide dihydrate, [Zn(C(6)H(14)N(2))(2)(H(2)O)(2)](C(4)H(4)NO(4)S)(2)·2H(2)O, (II), are two-dimensional hydrogen-bonded supramolecular complexes. In (I), the Cu(II) ion resides on a centre of symmetry in a neutral complex, in a tetragonally distorted octahedral coordination environment comprising four amine N atoms from cyclohexane-1,2-diamine ligands and two N atoms of two acesulfamate ligands. Intermolecular N-H...O and C-H...O hydrogen bonds produce R(2)(2)(12) motif rings which lead to two-dimensional polymeric networks. In contrast, the Zn(II) ion in (II) resides on a centre of symmetry in a complex dication with a less distorted octahedral coordination environment comprising four amine N atoms from cyclohexane-1,2-diamine ligands and two O atoms from aqua ligands. In (II), an extensive two-dimensional network of N-H...O, O-H...O and C-H...O hydrogen bonds includes R(2)(1)(6) and R(4)(4)(16) motif rings.

Structure of 4,4′-butane-(1,4,7-three-p-tolylsulphonyl-1,4,7-three amine) diphthalonitrile

Abstract The crystal structure of the title compound, C41 H35 N7 O6 S3 was determined as monoclinic by single crystal X-Ray diffraction technique. The molecular structure was identified by IR, 1H-NMR, 13C-NMR and elemental analysis. The crystal parameters of this compound are as follows: monoclinic P 2 1/n, a = 12.694(2) Å, b = 26.204(2) Å, c = 13.005(2) Å, β = 102.95(2)°, V = 4216.02(1) Å.3, Z = 4, Dx = 1.289 g/cm3, F(000) = 1704, λ (MoKα) = 0.71070 Å, μ = 0.2 mm−1. The structure was solved by SHELXS-97 and refined by SHELXL-97. R = 0.06 for 3178 observed reflections with I > 2σ (I).