فهرست مقالات NMR shielding

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  1 - An ab initio quantum chemical investigation of TOMS nmr SHIELDING TENSORS IN Adenine-thymine, Adenine-uracil, Guanine-Cytosine & uracil-quartet: comparison between theoretical and experimental results
  H. Aghaie M. Monajjemi Gh. Ghassemi M. Kia
  We have evaluated the NMR shielding tensors for A:T,G:C,A:U in Watson-crick, and U-quartet. We have computed NMR shielding tensors at B31YP level by using 6-31G(d) basis set. We have compute anisotropy and asymmetry in A:T,G:C,A:U and U-quartet. The NMR shielding tensor چکیده کامل

  We have evaluated the NMR shielding tensors for A:T,G:C,A:U in Watson-crick, and U-quartet. We have computed NMR shielding tensors at B31YP level by using 6-31G(d) basis set. We have compute anisotropy and asymmetry in A:T,G:C,A:U and U-quartet. The NMR shielding tensors were calculated using the GIAO method. The natural bonding orbital analysis (NBO) were performed. NBO calculation have been done at B31LYP level. We have evaluated lowest occupancy orbitals, highest energy, donor and acceptor atoms, core and valence orbitals, total Lewis, natural population in atoms in NBO calculation. پرونده مقاله
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  2 - Investigation of Solvent Effect on CUA Codon Mutation: NMR Shielding Study
  S. Irani M. Monajjemi S.M Atyabi M. Sadegizadeh M. Heshmat T. Nejadsattari
  P53 is one of the gene that has important role in human cell cycle and in the human cancers too.Models of codon substitution make it possible to separate mutational biases in the DNA fromselective constraints on the protein, and offer a great advantage over amino acid m چکیده کامل

  P53 is one of the gene that has important role in human cell cycle and in the human cancers too.Models of codon substitution make it possible to separate mutational biases in the DNA fromselective constraints on the protein, and offer a great advantage over amino acid models forunderstanding the evolutionary process of proteins and protein-coding DNA sequences. In thiswork, we investigated about CUA codon in exon5 of p53 that has mutated to CCA codon.We studied solvent effects on CUA codon by theoretical method, because the most of biologicalsystems studied in solution and solvents have essential role in mutation of genes. Five solventsconsist of acetone, ethanol, methanol, DMSO and water are predicated using ab initio method.Also, indirect (Au ind) solvent effects are obtained and NMR shielding tensors (ppm) have beencomputed with the continuous set of the gauge independent atomic orbital (GIAO) method. پرونده مقاله
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  3 - Theoretical study of hydrogen bond effects on Diphenylphosphorylazide
  S. Reihani Z. Azizi M. Khaleghian H. Passdar L. Pishkar R. Ahmadi L. Saedi
  The interaction of DPPA which is an important component in cellular membrane with molecules of water asmedia, cause some changes in geometry of DPPA .In this study we focused our attention on comparing thismolecule with related hydrated complexes employing different bas چکیده کامل

  The interaction of DPPA which is an important component in cellular membrane with molecules of water asmedia, cause some changes in geometry of DPPA .In this study we focused our attention on comparing thismolecule with related hydrated complexes employing different basis sets at hartree-fock levels of theory. Thetheoretical NMR shielding tensor of some imported atoms were also reported. پرونده مقاله
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  4 - An ab initio study of metalated CMP,UMP& dTMP at HF level:Bond energies and isotropic NMR shielding of atoms
  M.A Seyed Sajjadi R. Sayadi G. Ghasem KH. Kalateh
  The interaction of Magnesium hydrate at the phosphate oxygen atom of the pyrimidine nucleotides (CMP,UMP,dTMP) were studied at the Hartree-Fock level Theory. We used LANL2DZ basis set for Mg and 6-31g* basis set for atoms.The basis set superposition error (BSSE) begins چکیده کامل

  The interaction of Magnesium hydrate at the phosphate oxygen atom of the pyrimidine nucleotides (CMP,UMP,dTMP) were studied at the Hartree-Fock level Theory. We used LANL2DZ basis set for Mg and 6-31g* basis set for atoms.The basis set superposition error (BSSE) begins to converge for used Method/basis set. The gauge-invariant atomic orbital (GIAO) method and the continuous-set-of-gauge-transformation (CSGT) procedure were employed to calculate isotropic atomic shielding of the nucleotides using density functional theory at the B3LYP/6-31g** . These calculations yield molecular geometries in good agreement with available experimental data. پرونده مقاله
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  5 - Theoretical study of solvent effect on NMR shielding for Pyrazole and Pyrazoline
  Farideh Keshavarz Rezaei
  The physical and chemical properties of Pyrazole and Pyrazoline molecules were theoreticallystudied by Gaussian 03, software with NMR and Molecular orbital calculations at B3LYP/6-31G andB3LYP/6-31+G(d) levels, in gas phase and solution. In this study a comparison effec چکیده کامل

  The physical and chemical properties of Pyrazole and Pyrazoline molecules were theoreticallystudied by Gaussian 03, software with NMR and Molecular orbital calculations at B3LYP/6-31G andB3LYP/6-31+G(d) levels, in gas phase and solution. In this study a comparison effect of threesolvents with different dielectric constants on Pyrazole and Pyrazoline molecules in aspect energyinteraction between solute and solvent, and NMR shielding parameters (ppm) such as,
  Iso (
  Isotropic),
  Aniso (
  Anisotropic), anisotropic magnetic shielding tensor, 
  , chemical shift, , totalatomic charge and asymmetry parameter, , were performed. These parameters were calculated byusing the GIAO method. The results show solvent-induced shielding variation is more stronglyrelated to the intensity of the solvent reaction field rather than on the change of molecular geometryinduced by the solvent. پرونده مقاله