نتایج جستجو برای: 13c nmr

تعداد نتایج: 64598  

Journal: :Chemical science 2015
Y Zhang D Krylov M Rosenkranz S Schiemenz A A Popov

Paramagnetic and variable temperature 13C and 45Sc nuclear magnetic resonance studies are performed for nitride clusterfullerenes MSc2N@C80 with icosahedral Ih(7) carbon cage, where M runs through all lanthanides forming nitride clusters. The influence of the endohedral lanthanide ions on the NMR spectral pattern is carefully followed, and dramatic differences are found in peak positions and li...

Journal: :Journal of biomolecular NMR 2000
J J Balbach J Yang D P Weliky P J Steinbach V Tugarinov J Anglister R Tycko

We describe solid state NMR measurements on frozen solutions of the complex of the 24-residue HIV-1 gp120 V3 loop peptide RP135 with the Fab fragment of the anti-gp120 antibody 0.5beta, using rotational echo double resonance (REDOR). In order to probe possible hydrogen bonding between arginine side chains and glycine backbone carbonyls in the region of the conserved Gly-Pro-Gly-Arg (GPGR) motif...

Journal: :int. j. lignocellulosic products 2014
s.a. mirshokraie v. haji aghaei t. partovi s. noroozi

in this research, the characteristics of cmp dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13c nmr spectroscopy and dfrc degradation procedure. the results indicated that the main structural units in lignins are phenyl propane skeletons b...

Journal: :iranian journal of pharmaceutical sciences 0
marzieh matin yekta iau pharmaceutical sciences branch and department of pharmacognosy, institute of medicinal plants, acecr, tehran, iran seyed hamid reza alavi iau pharmaceutical sciences branch and department of pharmacognosy, institute of medicinal plants, acecr, tehran, iran

from hexanic extract of aerial parts of peucedanum ruthenicum m. bieb (apiaceae) collected from mazandaran province of iran, four triterpenoids namely taraxasterol, y-taraxasterol, poriferasterol and b-sitosterol have been isolated by column chromatography, thin layer chromatography, and crystallization. their structures were elucidated by spectroscopic methods (uv, ir, ms, 1h and 13c-nmr).

2014
Ryszard B. Nazarski

ABSTRACT Spin-lattice relaxation times, T1s, for 13C nuclei in two cations H n1n+ (n = 1, 5) of N-(2-aminoethyl)-cyclam (1, scorpiand) were determined by means of 13C{1H} NMR experiments in aqueous solution at pH 11.5 and 0.2. The theoretical study [modeling with OPLS-AA, B3LYP/6-31G(d) geometry optimizations, dispersion-corrected energies (DFT-D3), and DFT-GIAO predictions of the NMR chemical ...

Journal: :Neurochemistry international 2003
Gülin Oz Pierre Gilles Henry Elizabeth R Seaquist Rolf Gruetter

The concentration and metabolism of the primary carbohydrate store in the brain, glycogen, is unknown in the conscious human brain. This study reports the first direct detection and measurement of glycogen metabolism in the human brain, which was achieved using localized 13C NMR spectroscopy. To enhance the NMR signal, the isotopic enrichment of the glucosyl moieties was increased by administra...

Journal: :Biotechnology and bioengineering 1999
Klapa Park Sinskey Stephanopoulos

Proper analysis of label distribution in metabolic pathway intermediates is critical for correct interpretation of experimental data and strategic experimental design. While, for example, 13C nuclear magnetic resonance (NMR) spectroscopy is usually limited to the measurement of degrees of 13C enrichment, more information about metabolic fluxes can be extracted from the fine structure of NMR spe...

Journal: :The Biochemical journal 1996
W J Malaisse T M Zhang I Verbruggen R Willem

The generation of 13C-labelled lactate by colon carcinoma cells of the Caco-2 line incubated for 120 min in the presence of [2-13C]propionate (10 mM) was assessed by 13C NMR. About 10% of the total amount of 13C-labelled lactate was recovered in the cell pellet and displayed a [2-13C]lactate/[3-13C]lactate isotopomer ratio of 1.18 +/- 0.01. An even higher isotopomer ratio of 1.53 +/- 0.14 was o...

Journal: :NMR in biomedicine 2004
M Carmen Martínez-Bisbal Luis Martí-Bonmatí José Piquer Antonio Revert Pilar Ferrer José L Llácer Martial Piotto Olivier Assemat Bernardo Celda

High-resolution magic angle spinning (HR-MAS) one- and two-dimensional 1H and 13C nuclear magnetic resonance (NMR) spectroscopy has been used to study intact glioblastoma (GBM) brain tumour tissue. The results were compared with in vitro chemical extract and in vivo spectra. The resolution of 1H one-dimensional, 1H TOCSY and 13C HSQC HR-MAS spectra is comparable to that obtained on perchloric e...

A series of interesting sulfonamides containing hydroxyl group were synthesized under solvent-free conditions. The synthetic route involves the selective reaction of amino alcohol and sulfonating agents. The sulfonamides were obtained by simple procedure after an easy work-up in high yield and purity, and characterized by IR, 1H NMR and 13C NMR analysis. These compounds were tested for antibact...

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