The NMR hyperpolarization of uniformly 15N-labeled [15N3]metronidazole is demonstrated by using SABRE-SHEATH. In this antibiotic, the 15NO2 group is hyperpolarized through spin relays created by 15N spins in [15N3]metronidazole, and the polarization is transferred from parahydrogen-derived hydrides over six chemical bonds. In less than a minute of parahydrogen bubbling at approximately 0.4 μT, a high level of nuclear spin polarization (P15N) of around 16 % is achieved on all three 15N sites. This product of 15N polarization and concentration of 15N spins is around six-fold better than any previous value determined for 15N SABRE-derived hyperpolarization. At 1.4 T, the hyperpolarized state persists for tens of minutes (relaxation time, T1≈10 min). A novel synthesis of uniformly 15N-enriched metronidazole is reported with a yield of 15 %. This approach can potentially be used for synthesis of a wide variety of in vivo metabolic probes with potential uses ranging from hypoxia sensing to theranostic imaging.
|Журнал||Chemistry - A European Journal|
|Состояние||Опубликовано - 2 июл. 2019|