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Application of the Steady-State Variable Nutation Angle Method for Faster Determinations of Long T 1s-An Approach Useful for the Design of Hyperpolarized MR Molecular Probes.

Jupin M, Gamliel A, Hovav Y, Sosna J, Gomori JM, Katz-Brull R - Magn Reson Insights (2015)

Bottom Line: The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation.Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium.Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

ABSTRACT
In the dissolution-dynamic nuclear polarization technique, molecular probes with long T 1s are preferred. 13C nuclei of small molecules with no directly bonded protons or sp(3 13)C nuclei with proton positions substituted by deuterons may fulfill this requirement. The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation. Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium. Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

No MeSH data available.


13C spectra and structures of [UL-13C6, UL-2H8]2-deoxy-d-glucose and [UL-13C6, UL-2H7]d-glucose: (A) the chemical structures of the α and β anomers of [UL-13C6, UL-2H8]2-deoxy-d-glucose, (B) a 13C spectrum of [UL-13C6, UL-2H8]2-deoxy-d-glucose, showing the signals of the α and β anomers, (C) the chemical structures of the α and β anomers of [UL-13C6, UL-2H7]d-glucose, and (D) a 13C spectrum of [UL-13C6, UL-2H7]d-glucose, showing the signals of the α and β anomers. The marked signals were assigned according to previous reports.19–22Notes: *Indicates labeled 13C. D indicates deuterium (2H). The various 13C positions in both anomers are marked by numerals in the structures for convenience of reference.
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f1-mri-suppl.1-2015-041: 13C spectra and structures of [UL-13C6, UL-2H8]2-deoxy-d-glucose and [UL-13C6, UL-2H7]d-glucose: (A) the chemical structures of the α and β anomers of [UL-13C6, UL-2H8]2-deoxy-d-glucose, (B) a 13C spectrum of [UL-13C6, UL-2H8]2-deoxy-d-glucose, showing the signals of the α and β anomers, (C) the chemical structures of the α and β anomers of [UL-13C6, UL-2H7]d-glucose, and (D) a 13C spectrum of [UL-13C6, UL-2H7]d-glucose, showing the signals of the α and β anomers. The marked signals were assigned according to previous reports.19–22Notes: *Indicates labeled 13C. D indicates deuterium (2H). The various 13C positions in both anomers are marked by numerals in the structures for convenience of reference.

Mentions: The spectra of both the [UL-13C6, UL-2H8]2-deoxy-d-glucose and the [UL-13C6, UL-2H7]d-glucose compounds and their anomer structures are shown in Figure 1. The rational for selecting the integration regions described above is as follows. Because the measurements were recorded without decoupling of the proton or the deuterium interaction, the 13C signals of both the labeled molecules and the protonated isotopic impurity molecules appear split. Simulating these spin systems (Fig. 2) showed that the 13C resonances of the isotopic impurity and the labeled compound overlap. The region of overlap is shown in Figure 2, on the right-hand side of the major multiplet. For the analyses of T1, in order to avoid a possible effect of this overlap, we used an integration region consisting of the two most left-hand side peaks of the major multiplets, which were farthest from the overlapping isotopic impurity signals.


Application of the Steady-State Variable Nutation Angle Method for Faster Determinations of Long T 1s-An Approach Useful for the Design of Hyperpolarized MR Molecular Probes.

Jupin M, Gamliel A, Hovav Y, Sosna J, Gomori JM, Katz-Brull R - Magn Reson Insights (2015)

13C spectra and structures of [UL-13C6, UL-2H8]2-deoxy-d-glucose and [UL-13C6, UL-2H7]d-glucose: (A) the chemical structures of the α and β anomers of [UL-13C6, UL-2H8]2-deoxy-d-glucose, (B) a 13C spectrum of [UL-13C6, UL-2H8]2-deoxy-d-glucose, showing the signals of the α and β anomers, (C) the chemical structures of the α and β anomers of [UL-13C6, UL-2H7]d-glucose, and (D) a 13C spectrum of [UL-13C6, UL-2H7]d-glucose, showing the signals of the α and β anomers. The marked signals were assigned according to previous reports.19–22Notes: *Indicates labeled 13C. D indicates deuterium (2H). The various 13C positions in both anomers are marked by numerals in the structures for convenience of reference.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4629631&req=5

f1-mri-suppl.1-2015-041: 13C spectra and structures of [UL-13C6, UL-2H8]2-deoxy-d-glucose and [UL-13C6, UL-2H7]d-glucose: (A) the chemical structures of the α and β anomers of [UL-13C6, UL-2H8]2-deoxy-d-glucose, (B) a 13C spectrum of [UL-13C6, UL-2H8]2-deoxy-d-glucose, showing the signals of the α and β anomers, (C) the chemical structures of the α and β anomers of [UL-13C6, UL-2H7]d-glucose, and (D) a 13C spectrum of [UL-13C6, UL-2H7]d-glucose, showing the signals of the α and β anomers. The marked signals were assigned according to previous reports.19–22Notes: *Indicates labeled 13C. D indicates deuterium (2H). The various 13C positions in both anomers are marked by numerals in the structures for convenience of reference.
Mentions: The spectra of both the [UL-13C6, UL-2H8]2-deoxy-d-glucose and the [UL-13C6, UL-2H7]d-glucose compounds and their anomer structures are shown in Figure 1. The rational for selecting the integration regions described above is as follows. Because the measurements were recorded without decoupling of the proton or the deuterium interaction, the 13C signals of both the labeled molecules and the protonated isotopic impurity molecules appear split. Simulating these spin systems (Fig. 2) showed that the 13C resonances of the isotopic impurity and the labeled compound overlap. The region of overlap is shown in Figure 2, on the right-hand side of the major multiplet. For the analyses of T1, in order to avoid a possible effect of this overlap, we used an integration region consisting of the two most left-hand side peaks of the major multiplets, which were farthest from the overlapping isotopic impurity signals.

Bottom Line: The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation.Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium.Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

ABSTRACT
In the dissolution-dynamic nuclear polarization technique, molecular probes with long T 1s are preferred. 13C nuclei of small molecules with no directly bonded protons or sp(3 13)C nuclei with proton positions substituted by deuterons may fulfill this requirement. The T 1 determination of such new molecular probes is crucial for the success of the hyperpolarized observation. Although the inversion-recovery approach remained by and large the standard for T 1 measurements, we show here that the steady-state variable nutation angle approach is faster and may be better suited for the determination of relatively long T 1s in thermal equilibrium. Specifically, the T 1 of a new molecular probe, [uniformly labeled (UL)-13C6, UL-2H8]2-deoxy-d-glucose, is determined here and compared to that of [UL-13C6, UL-2H7]d-glucose.

No MeSH data available.