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Abstract Diazirine moieties are chemically stable and have been incorporated into biomolecules without impediment of biological activity. The15N2labeled diazirines are appealing motifs for hyperpolarization supporting relaxation protected states with long‐lived lifetimes. The (‐CH15N2) diazirine groups investigated here are analogues to methyl groups, which provides the opportunity to transfer polarization stored on a relaxation protected (‐CH15N2) moiety to1H, thus combining the advantages of long lifetimes of15N polarization with superior sensitivity of1H detection. Despite the proximity of1H to15N nuclei in the diazirine moiety,15NT1times of up to (4.6±0.4) min and singlet lifetimesTsof up to (17.5±3.8) min are observed. Furthermore, we found terminal diazirines to support hyperpolarized1H2singlet states in CH2groups of chiral molecules. The singlet lifetime of1H singlets is up to (9.2±1.8) min, thus exceeding1HT1relaxation time (at 8.45 T) by a factor of ≈100.
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Development of Dissolution Dynamic Nuclear Polarization of [ 15 N 3 ]Metronidazole: A Clinically Approved Antibiotic
Abstract We report dissolution Dynamic Nuclear Polarization (d‐DNP) of [15N3]metronidazole ([15N3]MNZ) for the first time. Metronidazole is a clinically approved antibiotic, which can be potentially employed as a hypoxia‐sensing molecular probe using15N hyperpolarized (HP) nucleus. The DNP process is very efficient for [15N3]MNZ with an exponential build‐up constant of 13.8 min using trityl radical. After dissolution and sample transfer to a nearby 4.7 T Magnetic Resonance Imaging scanner, HP [15N3]MNZ lasted remarkably long with T1values up to 343 s and15N polarizations up to 6.4 %. A time series of HP [15N3]MNZ images was acquired in vitro using a steady state free precession sequence on the15NO2peak. The signal lasted over 13 min with notably long T2of 20.5 s. HP [15N3]MNZ was injected in the tail vein of a healthy rat, and dynamic spectroscopy was performed over the rat brain. The in vivo HP15N signals persisted over 70 s, demonstrating an unprecedented opportunity for in vivo studies.
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- Award ID(s):
- 1904780
- PAR ID:
- 10425342
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 31
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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