The C(alpha) chemical shift tensors of proteins contain information on the backbone conformation. We have determined the magnitude and orientation of the C(alpha) chemical shift tensors of two peptides with a-helical torsion angles: the Ala residue in G*AL (phi = -65.7 degrees, psi = -40 degrees), and the Val residue in GG*V (phi = -81.5 degrees, psi = -50.7 degrees). The magnitude of the tenso...

In addition to the 5'-phosphate ester on its flavin mononucleotide (FMN) moiety, flavodoxin from Azotobacter vinelandii contains 2 moles of tightly bound phosphate. One non-coenzyme phosphate group is covalently bound to the protein, as it remains with the protein on acid precipitation, whereas the other phosphate is released. The invariance of the (31)P nuclear magnetic resonance chemical shif...

ABSTRACT Advances in Nuclear Magnetic Resonance (NMR) spectroscopy is a cornerstone structure elucidation of polycyclic 'cage' scaffolds. Due to the compactness these compounds, much overlap, as well unique through-space and bond NMR interactions are frequently observed. This review serves guide for future derivatives by providing some typical relevant aspects characteristic trends, substituent...

Substitution of two or four carbon atoms by nitrogen in the corannulene molecule as a carbon nanostructure was done and the obtained structures were optimized at MP2/6-31G(d) level of theory. Calculations of the nucleus-independent chemical shift (NICS) were performed to analyze the aromaticity of the corannulene rings and its derivatives upon doping with N at B3LYP/6-31G(d) level of theory. Re...

In this work, poly(lactic acid) (PLA) dimer model compounds with different tacticities were synthesized and studied in detail by 1H and 13C nuclear magnetic resonance (NMR) in three solvents, deuterated chloroform (CDCl3)/CCl4 (20/80 v/v), CDCl3 and dimethyl sulfoxide -d6. All of the peaks in the 1H and 13C NMR spectra were assigned with the help of two-dimensional NMR. Although the solvents we...

The spectral parameters of the nuclear magnetic resonance (NMR) spectra are dependent on the chemical environment around the nuclei, making NMR spectroscopy a powerful method for studying molecular structure and dynamics at the atomic level. Conversely, the spectral parameters can be calculated if one knows the molecular structure. The spectral parameter prediction plays a key role in many appl...

A recently developed nuclear double resonance technique which permits sensitive detection, together with high resolution, of rare spins in solids or other dipolar-coupled nuclear systems [Pines, Gibby, and Waugh (1973) J. Chem. Phys. 59, 569] has been applied to the study of natural abundance (13)C-nuclear magnetic resonance in lipid mesophases and of selectively labeled carbon sites in bacteri...

in this research, the magnetite nanoparticles (fe304) were prepared by coprecipitation of fe- andginger is a well known spice and flavoring agent which has also been used in traditional medicine inmany countries. ginger contains essential oils including gingerol and zingiberene. it also containspungent principles such as zingerone, and shogaol. in the paper six theoretical methods were used toc...