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Achieving High Levels of NMR-Hyperpolarization in Aqueous Media With Minimal Catalyst Contamination Using SABRE.

ABSTRACT: Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced ¹ H?NMR signals in a range of substrates in aqueous media. To achieve this outcome, phase-transfer catalysis is exploited, which leads to less than 1.5×10^-6 ?mol dm^-3 of the iridium catalyst in the aqueous phase. These observations reflect a compelling route to produce a saline-based hyperpolarized bolus in just a few seconds for subsequent in vivo MRI monitoring. The new process has been called catalyst separated hyperpolarization through signal amplification by reversible exchange or CASH-SABRE. We illustrate this method for the substrates pyrazine, 5-methylpyrimidine, 4,6-d₂ -methyl nicotinate, 4,6-d₂ -nicotinamide and pyridazine achieving ¹ H signal gains of approximately 790-, 340-, 3000-, 260- and 380-fold per proton at 9.4?T at the time point at which phase separation is complete.

SUBMITTER: Iali W

PROVIDER: S-EPMC5582620 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

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Achieving High Levels of NMR-Hyperpolarization in Aqueous Media With Minimal Catalyst Contamination Using SABRE.

Iali Wissam W Olaru Alexandra M AM Green Gary G R GGR Duckett Simon B SB

Chemistry (Weinheim an der Bergstrasse, Germany) 20170719 44

Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced 1 H NMR signals in a range of substrates in aqueous media. To achieve this outcome, phase-transfer catalysis is exploited, which leads to less than 1.5×10-6 mol dm-3 of the iridium catalyst in the aqueous phase. These observations reflect a compelling route to produce a saline-based hyperpolarized bolus in just a few seconds for subsequent in vivo MRI monitoring. Th ...[more]

PMID: 28609572

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