Suchergebnisse

For the relationship between thermodynamic parameters, global hardness, global electronegativity, anomeric effect, structural parameters, and structural properties of dodecahedro-spiro [isochromene-3,2'-pyran] (A), dodecahedro-spiro [isothiocromene-3,2'- thiopyran) (B), dodecahedro-spiro [isochroman-3,2'-thiopyran] (C) and dodecahedro-spiro [isothiochrome-3,2'-pyran] (D) computational methods (B3LYP / 6-311 ++ G **) were used. Results show that the calculated Gibbs free energy and enthalpy differences between the axial- and equatorial- stereoisomers [i.e. ΔG = Geq – Gax, ΔH = Heq- Hax] decrease from compound A to compound B and from compound C to compound D. NBO results show that the anomeric effect associated with the electron delocalization is in benefit of the axial-stereoisomers and with the decrease of the anomeric effect, the values of global hardness (η), and global electronegativity (χ), from compound A to compound B and from compound C to Composition D is also decrease. The correlations between the global hardness, global electronegativity, anomeric effect, structural parameters, and thermodynamic parameters [ΔH, ΔG, and ΔS] of compounds A-D have been investigated. Also, it can be concluded that the stability energy obtained from the numerical values of the anomeric effect and the values calculated theoretically (B3LYP / 6-311 ++ G **) confirmed each other.

Ag2O/GO/TiO2 composite nanostructure was established as a heterogeneous catalyst for the one pot synthesis of dihydropyridine derivatives via Hantzsch reaction. The synthetic method was mainly used in the presence of Ag2O/GO/TiO2 nano composite as a heterogeneous solid catalyst. This nano composite catalyzed Hantzsch reaction afforded good yields (87–95%) in solvent free condition at 90 °C. A broad range of structurally diverse aldehydes were applied successfully, and corresponding products were obtained in high yields without any byproduct. Compared with other methods, satisfactory results are obtained with high yields, short reaction times, and simplicity in the experimental procedure. Cytotoxic activities for some of the synthesized compounds were evaluated by MTT assay in three human cancer cell lines (HeLa, LS180 and Raji). Half of the tested compounds showed good cytotoxicity in Raji cells. Diethyl 4-(2,4-dichlorophenyl)-1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate (3 i) was found to be the most potent molecule among the studied 1, 4 dihydropyridines derivatives. Electron withdrawing groups along with heterocyclic rings bearing more hetero atoms seemed to be necessary factors in providing higher cytotoxic activities in Raji cell lines.

In order to measure the effect of graphene oxide-stabilized drug on the growth of microorganisms, first the graphene oxide used was prepared from graphite modified by Homers method. After preparation of graphene carrier, doxorubicin was loaded by ultra sound. Then, due to the high biocompatibility of drug carriers, their cytotoxicity and antibacterial properties were determined by the methods of minimum inhibitory concentration, minimum bactericidal concentration and plate penetration. The effect of prepared carriers containing metal nanoparticles on the growth of microorganisms such Enterococcus, Corynebacterium and Escherichia coli were studied as statistical means. The best minimum inhibitory concentration (MIC) values were obtained for Fe/Ag/M (rGO/Cis) nanoparticles, which had a lower minimum concentration compared to other nanoparticles or their combinations. Among these, the rGO/Cis sample had the best performance. Bacteria of Corynebacterium and Enterococcus showed the greatest reduction in viability against RGO / Cis up to 125 and 62.5 μg/mL, respectively. Carriers prepared in this study were generally not very toxic, as a high percentage of cells survived in the concentration range less than 100 μg/mL.