Use of 13C chemical shift surfaces in the study of carbohydrate conformation. Application to cyclomaltooligosaccharides (cyclodextrins) in the solid state and in solution

O’Brien, Edward P.; Moyna, Guillermo

doi:10.1016/j.carres.2003.09.034

Cited by 21 publications

(25 citation statements)

References 43 publications

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“…The NMR rotors were therefore dried in oven before the experiments, and the milled powder was also dried at 80°C on a kofler bench before filling in the NMR rotor, in order to prevent accidental humidity adsorption. [24][25][26]). The NMR lines attributed to galactose C 1 and glucose C' 1 ( or ) carbons remain however sufficiently resolved to be quantitatively exploited.…”

Section: Resultsmentioning

confidence: 99%

Mutarotational kinetics and glass transition of lactose

Lefort

Caron

willart

et al. 2006

Solid State Communications

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We report for the first time real time in situ and quantitative measurements of the mutarotation reaction of lactose in the solid state. The experiments have been performed by 13 C NMR. We show that mutarotation is initiated on heating the amorphous state, and reaches chemical equilibrium close above the glass transition temperature T g . We do not observe this transformation when starting from stable crystalline states. The final ratio of  and  anomers is 1:1, which suggests that the energy profile of the mutarotation reaction pathway in the solid state is actually different from the mechanism proposed for aqueous solution. This chemical equipartition is reached before the crystallization into the corresponding 1:1 molecular compound. These new data clearly illustrate the interrelation between the chemical molecular properties, the physical state of the material, and the relaxational dynamics of the glass.

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Section: Resultsmentioning

confidence: 99%

Mutarotational kinetics and glass transition of lactose

Lefort

Caron

willart

et al. 2006

Solid State Communications

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“…Several methods have been proposed in the literature [7,18], including series expansions on a trigonometric basis. In the present work, reliable data have been provided by using simple cubic spline The last step of data processing is the convolution of S() with a lorentzian function, in order to account for the homogeneous CPMAS linewidth.…”

Section: mentioning

confidence: 99%

“…The starting crystal structure was relaxed by molecular mechanics in order to identify the lowest energy molecular conformation (LMC) in a given force field. For each different force field here used, an adiabatic Ramachandran map E(,) was calculated by classically mapping the whole (,) space by 324 (=18 x 18) points separated by 20° steps [5][6][7]. For each (,) point in the map, minimization started from the LMC coordinates, then the  and  values were set and restrained by setting a high value of dihedral angle spring constants.…”

Section: Conformational Energy Mapsmentioning

confidence: 99%

“…This average can be either evaluated by a statistical model [6], or by exploring the E() map by molecular dynamics [7]. The accuracy of the results is therefore highly dependent on the validity and precision of three parameters: the Ramachandran map E(), the chemical shift map (), and the dynamical average.…”

Section: Introductionmentioning

confidence: 99%

“…carbohydrates [5][6][7]. In solution NMR studies, it is often assumed that molecular conformations are explored over time with a probability governed by E(), and that the measured isotropic chemical shift is equal to the mean value obtained by averaging the ()…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exploring the conformational energy landscape of glassy disaccharides by cross polarization magic angle spinning C13 nuclear magnetic resonance and numerical simulations. II. Enhanced molecular flexibility in amorphous trehalose

Lefort

Bordat

Cesàro

et al. 2007

The Journal of Chemical Physics

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Calculating nuclear magnetic resonance chemical shifts in solvated systems

Casabianca

2020

Magnetic Reson in Chemistry

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The nuclear magnetic resonance (NMR) chemical shift is extremely sensitive to molecular geometry, hydrogen bonding, solvent, temperature, pH, and concentration. Calculated magnetic shielding constants, converted to chemical shifts, can be valuable aids in NMR peak assignment and can also give detailed information about molecular geometry and intermolecular effects. Calculating chemical shifts in solution is complicated by the need to include solvent effects and conformational averaging. Here, we review the current state of NMR chemical shift calculations in solution, beginning with an introduction to the theory of calculating magnetic shielding in general, then covering methods for inclusion of solvent effects and conformational averaging, and finally discussing examples of applications using calculated chemical shifts to gain detailed structural information.

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Use of 13C chemical shift surfaces in the study of carbohydrate conformation. Application to cyclomaltooligosaccharides (cyclodextrins) in the solid state and in solution

Cited by 21 publications

References 43 publications

Mutarotational kinetics and glass transition of lactose

Mutarotational kinetics and glass transition of lactose

Exploring the conformational energy landscape of glassy disaccharides by cross polarization magic angle spinning C13 nuclear magnetic resonance and numerical simulations. II. Enhanced molecular flexibility in amorphous trehalose

Calculating nuclear magnetic resonance chemical shifts in solvated systems

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