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15 N hyperpolarisation of the antiprotozoal drug ornidazole by Signal Amplification By Reversible Exchange in aqueous medium
Author(s) -
Iali Wissam,
Moustafa Gamal A. I.,
Dagys Laurynas,
Roy Soumya S.
Publication year - 2021
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.5144
Subject(s) - chemistry , spin isomers of hydrogen , ornidazole , aqueous solution , spins , proton , heteronuclear molecule , hyperpolarization (physics) , nuclear magnetic resonance , chemical physics , analytical chemistry (journal) , nuclear magnetic resonance spectroscopy , stereochemistry , hydrogen , physics , organic chemistry , chromatography , condensed matter physics , quantum mechanics
Signal amplification by reversible exchange (SABRE) offers a cost‐effective route to boost nuclear magnetic resonance (NMR) signal by several orders of magnitude by employing readily available para ‐hydrogen as a source of hyperpolarisation. Although 1 H spins have been the natural choice of SABRE hyperpolarisation since its inception due to its simplicity and accessibility, limited spin lifetimes of 1 H makes it harder to employ them in a range of time‐dependent NMR experiments. Heteronuclear spins, for example, 13 C and 15 N, in general have much longer T 1 lifetimes and thereby are found to be more suitable for hyperpolarised biological applications as demonstrated previously by para ‐hydrogen induced polarisation (PHIP) and dynamic nuclear polarisation (DNP). In this study we demonstrate a simple procedure to enhance 15 N signal of an antibiotic drug ornidazole by up to 71,000‐folds with net 15 N polarisation reaching ~23%. Further, the effect of co‐ligand strategy is studied in conjunction with the optimum field transfer protocols and consequently achieving 15 N hyperpolarised spin lifetime of >3 min at low field. Finally, we present a convenient route to harness the hyperpolarised solution in aqueous medium free from catalyst contamination leading to a strong 15 N signal detection for an extended duration of time.