the thermodynamic functions such as enthalpy (h), gibbs free energy (g) and entropy (s) of serineand threonine amino acids were theoretically studied at different condition (solvents andtemperatures) by using gussian o3, software. first, the structural optimization of isolated serine andthreonine were done in the gas phase by using the hartree-fock (hf) level of theory with 3-21g, 6-31g and 6-3...

The thermodynamic functions such as enthalpy (H), Gibbs free energy (G) and entropy (S) of Serineand Threonine amino acids were theoretically studied at different condition (solvents andtemperatures) by using Gussian o3, software. First, the structural optimization of isolated Serine andThreonine were done in the gas phase by using the Hartree-Fock (HF) level of theory with 3-21G, 6-31G and 6-3...

The thermodynamic functions such as enthalpy, H°, Gibbs free energy, G°, and entropy, S°, of Arginine and Lysine amino acids were theoretically studied at different polar solvents by using ²Gaussian o3², software. First, the structural optimization of isolated Arginine and Lysine were done in the gas phase by applying the Density Functional Theory (B3LYP) level ...

Using Gaussian 03, software the thermodynamic functions such as Gibbs free energy, G, Enthalpy, H, and Entropy, S, of Alanine and Valine amino acids were theoretically studied at different solvents. First, the Density Functional Theory (B3LYP) level with 3-21G, 6-31G and 6-31+G basis sets were employed to optimization of isolated Alanine and Valine amino acids in the gas phase. Moreover, Vib...

Antioxidants are compounds which can prevent biological and chemical substances from oxidative damage by reactive oxygen species. Flavonoids are the most important class of polyphenolic compounds that because of their antioxidant characters possess biological activities and pharmacological effects. Chrysin-6-C-fucopyranoside and chrysin-3-malonyl-6-C-fucopyranoside are mono C-glycosyl derivativ...

using gaussian 03, software the thermodynamic functions such as gibbs free energy, g, enthalpy, h, and entropy, s, of alanine and valine amino acids were theoretically studied at different solvents. first, the density functional theory (b3lyp) level with 3-21g, 6-31g and 6-31+g basis sets were employed to optimization of isolated alanine and valine amino acids in the gas phase. moreover, vib...

nanopartmles have been used as an approach to improve the pharmacodynamic and phannacokinetie propertiesof various drues. amino acids have been considered to be useful to make such nano particles because ofthocompatithe and biodegradable characteristic. the quantum mechanical method that was chosen to analyze inethio hexa peptide nano ring]. the structure of some peptide nanorrigs as well as th...

Metal-free hydrogenation of imines by phosphonium borate zwitterion R2PH(CQF4)BH(C6F5)2 (1, R = CH3, tBu), has been studied by density functional theory (DFT) calculations. The study elucidates a two-step mechanism in which protonation of an imine by the phosphonium part of 1 is followed by hydride transfer to the C center from the borohydride part of 1. According to our calculations, the hydri...

Theoretical studies based on the density functional theory (DFT) have been performed to study structural and vibrational properties of free base, cationic, hydrochloride species narcotic tramadol agent in gas phase aqueous solution. In both media, B3LYP/6-31G* calculations were used while solution, self-consistent reaction field (SCRF) method together with integral equation formalism variant po...

In this study, the interactions of two effective derivatives methotrexate anticancer drug with Single-wall carbon nanotubes (SWNTs) and Boron nitride (BNNTs) in gas phase were investigated using DFT calculations. Through method, effects different solvents on interaction SWNTs BNNTs within Onsager self-consistent reaction field (SCRF) model, as well temperature stability between compounds variou...