A biased-potential molecular dynamics simulation method, accelerated molecular dynamics (AMD), was combined with the chemical shift prediction algorithm SHIFTX to calculate (1)H(N), (15)N, (13)Calpha, (13)Cbeta, and (13)C' chemical shifts of the ankyrin repeat protein IkappaBalpha (residues 67-206), the primary inhibitor of nuclear factor kappa-B (NF-kappaB). Free-energy-weighted molecular ense...

Several inconsistencies have been noted during recent systematic studies of the validity of additivity relationships (1-6) in the C chemical shifts of substituted pyridines. These showed that substantial errors could be introduced if care is not taken to use, for a given solvent, approximately the same concentration for all solutes; in our case this applied to monosubstituted and polysubstitute...

We report a 67Zn nuclear magnetic resonance (NMR) study of compounds containing zinc ions coordinated by oxygen, nitrogen, and sulfur ligands. New information concerning 67Zn nuclear quadrupole coupling constants (NQCC) and chemical shift was obtained from magic-angle spinning (MAS) spectra of solid compounds containing both natural abundance and enriched 67Zn isotopes. Rapid ligand exchange pr...

Fig. 2: Illustration of the shift distance of the water peaks between 23.5 and 39.5 °C (0.095 ppm) adjusted by Cr/PCr at 3.02 ppm as temperature independent reference. Due to the excessive intensity of water the other resonances were presented with a magnification factor of 1500. Fig. 3: Correlation between temperature and chemical shift distance of the H2O signal compared to tCho (a) and Cr/PC...

Sterically stabilized superparamagnetic iron oxide nanoparticles (SPIONs) were incubated with fresh human erythrocytes (red blood cells [RBCs]) to explore their potential application as magnetic resonance imaging contrast agents. The chemical shift and linewidth of (133)Cs(+) resonances from inside and outside the RBCs in (133)Cs nuclear magnetic resonance spectra were monitored as a function o...

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

equilibrium geometry, electronic structures, and vibrational modes of cob8- were investigated in the pbepbe/6-311+g(d,p) level of theory. the nucleus independent chemical shift (nics) analysis and magnetizability values were used for studying of aromaticity in cob8-. the effects of different solvents on the structure and frontier orbital energies were calculated using the polarizable continuum ...

The synthesis of an antiaromatic tetraoxa[8]circulene annulated with four perylene diimides (PDI), giving a dynamic non-planar π-conjugated system, is described. molecule contains 32 aromatic rings surrounding one formally planarized cyclooctatetraene (COT). intense absorption (ϵ=3.35×105 M−1 cm−1 in CH2Cl2) and emission bands are assigned to internal charge-transfer transitions the combined PD...