Coherence Transfer in Spatially Resolved NMR

Chandrakumar, N.

doi:10.4137/mri.s992

Cited by 5 publications

(6 citation statements)

References 42 publications

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“…Here E is the unity product operator for corresponding spin system. Then the normalized FID form is Table. In Table, the added FID values depend on θ and these results are the same with those of DEPT NMR experiment [4,12]. On the other hand, the subtracted results give the FID values for quaternary carbons in addition to CD, CD 2 and CD 3 groups.…”

Section: Discussionsupporting

confidence: 65%

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A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

2011

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Distortionless enhancement by polarization transfer including the detection of quaternary nuclei is a carbon-editing pulse NMR experiment. In this experiment multiplicity information for all carbons including quaternary carbons are obtained. In the present study, analytical descriptions of DEPTQ NMR experiment have been investigated for weakly coupled IS n (I = 1/2; S = 1; n = 0, 1, 2, 3) spin systems by using the product operator theory. Then, the theoretical discussion and the experimental suggestions for sub-spectral editing of C, CD, CD 2 and CD 3 groups have been presented. The comparison of the obtained results with those of the basic distortionless enhancement by polarization transfer NMR experiment has been also performed for CD n groups. It is shown that DEPTQ experiment can be also used for CD n groups.

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Section: Discussionsupporting

confidence: 65%

“…DEPT experiment is used to edit 13 C NMR spectra into subspectra containing protonated and deuterated carbonyl groups [3,4]. Distortionless enhancement by polarization transfer including the detection of quaternary nuclei (DEPTQ) experiment was developed by Burger and Bigler [5].…”

Section: Introductionmentioning

confidence: 99%

A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

2011

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“…Here, selective 1D TOCSY spectra obtained by use of the MLEV17 spin lock scheme10–12 were recorded as a time‐efficient means to monitor the build‐up of relayed magnetization intensity. Except for the simplest of spin systems,7b, 13–15 the description of the magnetization transfer during isotropic mixing is a complicated matter and relies on numerical simulations 16. 17 Fortunately, the kinetics of the transfer in linear spin systems such as those of monosaccharides (Figure 2) are sufficiently simplified to afford a qualitative picture.…”

Section: Resultsmentioning

confidence: 99%

Rapid Identification of Common Hexapyranose Monosaccharide Units by a Simple TOCSY Matching Approach

Gheysen

Mihai

Conrath

et al. 2008

Chemistry A European J

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Solution NMR spectroscopy is a well established technique for non-destructive characterization of the structures and conformations of complex oligo- and polysaccharides. One of the key experiments involves the use of 2D TOCSY to collect the 1H spins into groups that can be associated with the individual saccharide units that are present in the molecule under study. It is well known that the magnetization transfer rate through the 1H spin system during the TOCSY spin lock period is sensitive to the intervening 3J(H,H) scalar couplings, and therefore also to the saccharide stereochemistry. Here, we have investigated the potential to extract information on the stereochemistry of hexapyranose monosaccharide units directly from TOCSY spectra. Through a systematic experimental investigation of the magnetization transfer initiated from the anomeric 1H resonance in D-glucose, D-galactose and D-mannose it is shown that a 100 ms spin lock time provides optimal spectroscopic discrimination between these three commonly occurring building blocks. A simple matching scheme is proposed as a new tool for rapid attribution of the TOCSY traces originating from the anomeric 1H resonances towards the underlying monosaccharide type. The scheme appears robust with regard to structural variations and fairly tolerant to incidental overlap. Its application provides useful guidance during the subsequent NMR assignment process, as demonstrated with the PS7F polysaccharide from Streptococcus pneumonia. In addition, we show that our scheme affords a clear-cut distinction between the alpha- and beta-epimers of D-mannose-type units, which can be difficult to discriminate by NMR analysis. Application to the N-glycan 100.2 demonstrates the potential and wide applicability of this new discrimination approach.

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“…Obviously these cannot be explained by using the typical NMR vector model and require extensive calculation if one uses either density matrix or operator product formalism. Distortionless Enhancement by Polarization Transfer (DEPT) experiment is widely used to simplify spectra of carbonyl groups in complex molecules [6,15,16,17]. DEPT experiment results in an enhancement of the intensity of the low natural abundance X-nuclei (such as carbon) by using nuclei of high natural abundance (such as hydrogen).…”

Section: Dept Experiments For Two-spin Systemmentioning

confidence: 99%

A New Graphical User Interface for Teaching NMR

Hassan¹,

Nabulsi²

2014

EDUCATION

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The classical Nuclear Magnetic Resonance (NMR) vector model is known to be very effective and useful in teaching basic NMR 1D pulse sequences such as spin echo. For more complicated spin systems, density matrix calculation is often used. This method is known to be very complicated and not easy to follow after couple steps. Students usually get lost within the calculation and loose the physical meaning of the effect of different NMR pulses and other operations (chemical shifts, scalar-couplings) on the spin-system under investigation. As a compromise, another methodology has been developed which depends on the spin angular momentum operators. This is known as product operator formalism which involves less mathematical calculations, but still requires the user to know the correct outcome of different NMR pulses, scalar couplings and chemical shifts on different spin operators. We have developed product operator graphical user interface (OP-GUI) using MATLAB software that is capable of calculating product operators of up to four-coupled ½ spin systems. The effect of NMR pulses, scalarcoupling and chemical shifts on the spin system under investigation can be easily calculated. In this paper, several examples are given as prove of concept to show the capability and flexibility of the obtained OP-GUI in dealing with spin systems. We believe the obtained calculator is an effective teaching tool for new students in NMR and will help them to better understand and interpret complicated NMR pulse sequences applied on up to four weakly coupled ½ spin systems.

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Coherence Transfer in Spatially Resolved NMR

Cited by 5 publications

References 42 publications

A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

Rapid Identification of Common Hexapyranose Monosaccharide Units by a Simple TOCSY Matching Approach

A New Graphical User Interface for Teaching NMR

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Coherence Transfer in Spatially Resolved NMR

Cited by 5 publications

References 42 publications

A Product Operator Theory of DEPTQ NMR Spectroscopy for ISn(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

A Product Operator Theory of DEPTQ NMR Spectroscopy for ISn(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

Rapid Identification of Common Hexapyranose Monosaccharide Units by a Simple TOCSY Matching Approach

A New Graphical User Interface for Teaching NMR

Contact Info

Product

Resources

About

A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

A Product Operator Theory of DEPTQ NMR Spectroscopy for IS_n(I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems