Molecular Dynamics of Polycrystalline Cellobiose Studied by Solid-State NMR

Tang, Huiru; Belton, Peter

doi:10.1006/snmr.2002.0052

Cited by 22 publications

(35 citation statements)

References 50 publications

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“…It is often combined with measurement of T 1 to characterize the average mobility of the molecule protons. [21,22] For TAs, the second moment decreases with temperature, which is in agreement with the increasing mobility when temperature increases. In these conditions, the side chains are more mobile, thus minimizing the dipolar interactions in the system, and leading to a decrease in M 2 .…”

Section: Discussionsupporting

confidence: 81%

“…The break in the slope of the curve of tristearin α is directly linked to the mobility of the molecule, since M 2 is correlated with its correlation time. [21,22] If a molecular motion is really present for the tristearin in the α form, a minimum for the T 1 measurement should confirm this result because a break in the slope of the M 2 curve can be correlated with a minimum T 1 . These two parameters have already been used to determine the glass phase transition temperature, [19,30] to distinguish the mobility of specific sites [27,28,33] and to study the molecular motion of crystallized compounds.…”

Section: Discussionmentioning

confidence: 75%

“…These two parameters have already been used to determine the glass phase transition temperature, [19,30] to distinguish the mobility of specific sites [27,28,33] and to study the molecular motion of crystallized compounds. [21,22] No minimum was obtained for the β polymorphs, while a linear increase was observed for each TA in the temperature range studied. These results are in agreement with those obtained by Gibon et al [14] , who reported a minimum T 1 at −168…”

Section: Discussionmentioning

confidence: 84%

“…The values obtained for the two forms were consistent with those found for other crystallized systems. [21,22,27,28] The differences between the M 2 values of the two polymorphs can be explained by a difference in mobility between the two polymorphs. The α polymorph displays a less compact crystalline organization compared to the β polymorph.…”

Section: Discussionmentioning

confidence: 98%

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Study of triacylglycerol polymorphs by nuclear magnetic resonance: effects of temperature and chain length on relaxation parameters

Adam-Berret¹,

Rondeau-Mouro²,

Riaublanc³

et al. 2008

Magnetic Reson in Chemistry

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It is very important to monitor the characteristics of triacylglycerol crystal network in fats, as these crystals have an impact on many food properties such as texture, sensory taste, and extended shelf life. Although time-domain NMR (TD-NMR) is now the reference technique to determine the solid fat index in food, the entire possibilities of this technique are not used. Some NMR studies have been performed to determine its power for the discrimination of polymorphism. In this study, extended investigations proved that TD-NMR could evaluate triacylglycerol (TA) polymorphism, independently from temperature and chain length. Study of the dipolar interactions through second moment M(2), which is characteristic of proton mobility in solid-state samples, provided a new understanding of the structural organization of crystal molecules. Proton spin-lattice relaxation, which has been proved to be a true probe of polymorphism, has provided information on crystal networks. Combination of the two techniques revealed two very interesting kinds of results, i.e. the presence of a minimum spin-lattice relaxation time T(1) for tristearin alpha, which is a characteristic of a dynamic molecular process, and differences in behavior between long and short chain lengths, both at a molecular and a crystal level.

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Section: Discussionsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 98%

See 2 more Smart Citations

Study of triacylglycerol polymorphs by nuclear magnetic resonance: effects of temperature and chain length on relaxation parameters

Adam-Berret¹,

Rondeau-Mouro²,

Riaublanc³

et al. 2008

Magnetic Reson in Chemistry

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“…A few examples are discussed in this section. In 2000, Tang and co-workers coined the term proton relaxation-induced spectral editing (PRISE) for a set of 1 H relaxation-sensitive MAS NMR techniques to dissect the dynamics of plant cell walls and other biological materials [84,87,148]. Figure 11A shows a subsequent application to polysaccharides in native starch granules [87].…”

Section: Other Applications and Examplesmentioning

confidence: 99%

Hidden motions and motion-induced invisibility: Dynamics-based spectral editing in solid-state NMR

Matlahov

Wel

2018

Methods

188

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Solid-state nuclear magnetic resonance (ssNMR) spectroscopy enables the structural characterization of a diverse array of biological assemblies that include amyloid fibrils, non-amyloid aggregates, membrane-associated proteins and viral capsids. Such biological samples feature functionally relevant molecular dynamics, which often affect different parts of the sample in different ways. Solid-state NMR experiments' sensitivity to dynamics represents a double-edged sword. On the one hand, it offers a chance to measure dynamics in great detail. On the other hand, certain types of motion lead to signal loss and experimental inefficiencies that at first glance interfere with the application of ssNMR to overly dynamic proteins. Dynamics-based spectral editing (DYSE) ssNMR methods leverage motion-dependent signal losses to simplify spectra and enable the study of sub-structures with particular motional properties.

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Free radicals and their electron spin relaxation in cellobiose. X-band and W-band ESR and electron spin echo studies

Wencka

Wichlacz²,

Kasprzyk³

et al. 2006

Cellulose

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By use of 9.7 GHz and 94 GHz ESR spectra and electron spin echo (ESE)-detected spectra the six radical centres produced by c-irradiation of cellobiose were identified. The radicals are localized on different carbon atoms. Use of high-frequency ESR spectra with computer resolution enhancement methods enabled unique radical identification and determination of g-factors and proton hyperfine splitting, A, with high accuracy. For radiation doses below 20 kGy three radicals dominate: on C 1 with isotropic doublet A = 1.8 mT; on C 2 , C 3 and C 4 with triplet A = 2.9 mT; and localized on CH 2 with anisotropic triplet. For doses above 100 kGy the radical on C 1 dominates, because of cleavage of the glycosidic bonds. Electron spin-lattice relaxation shows that radiation damage of the cellulose structure around the radical centres is significant and radical molecules do not participate in phonon dynamics of the host lattice. The relaxation is because of tunnelling motions of the ring or OH-groups, with tunnelling splitting 2.4 cm -1 . Electron spin echo dephasing results identify cellobiose ring torsions with activation energy 117 cm -1 .

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Molecular Dynamics of Polycrystalline Cellobiose Studied by Solid-State NMR

Cited by 22 publications

References 50 publications

Study of triacylglycerol polymorphs by nuclear magnetic resonance: effects of temperature and chain length on relaxation parameters

Study of triacylglycerol polymorphs by nuclear magnetic resonance: effects of temperature and chain length on relaxation parameters

Hidden motions and motion-induced invisibility: Dynamics-based spectral editing in solid-state NMR

Free radicals and their electron spin relaxation in cellobiose. X-band and W-band ESR and electron spin echo studies

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