Continuous Re‐hyperpolarization of Nuclear Spins Using Parahydrogen: Theory and Experiment

Hövener, Jan‐Bernd; Knecht, Stephan; Schwaderlapp, Niels; Hennig, Jürgen; Elverfeldt, Dominik von

doi:10.1002/cphc.201402177

Cited by 48 publications

(64 citation statements)

References 57 publications

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“…. Labelled D -ribofuranose 1,2- 2 H,3,5-tetraacetate (precursor to Vorbrüggen glycosylation) was synthesized from D-[2- 2 H]-ribose (purchased from Omicron Biochemicals) according to Begley et al 41. Double labelled 13 C- 2 H nicotinamide riboside was synthesized from 13 C-nicotinamide and D -ribofuranose 1,2- 2 H,3,5-tetraacetate according to Vorbrüggen’s methodology described by Sobol et al 42…”

Section: Methodsmentioning

confidence: 99%

NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells

et al. 2016

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NAD+ is a vital redox cofactor and a substrate required for activity of various enzyme families, including sirtuins and poly(ADP-ribose) polymerases. Supplementation with NAD+ precursors, such as nicotinamide mononucleotide (NMN) or nicotinamide riboside (NR), protects against metabolic disease, neurodegenerative disorders and age-related physiological decline in mammals. Here we show that nicotinamide riboside kinase 1 (NRK1) is necessary and rate-limiting for the use of exogenous NR and NMN for NAD+ synthesis. Using genetic gain- and loss-of-function models, we further demonstrate that the role of NRK1 in driving NAD+ synthesis from other NAD+ precursors, such as nicotinamide or nicotinic acid, is dispensable. Using stable isotope-labelled compounds, we confirm NMN is metabolized extracellularly to NR that is then taken up by the cell and converted into NAD+. Our results indicate that mammalian cells require conversion of extracellular NMN to NR for cellular uptake and NAD+ synthesis, explaining the overlapping metabolic effects observed with the two compounds.

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Section: Methodsmentioning

confidence: 99%

NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells

et al. 2016

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“…Relaxation was neglected and rotation operators were applied to mimic the effect of radio frequency pulses. To assess the effect of erroneous intervals, flip angles and J -couplings, these parameters were varied3147.…”

Section: Methodsmentioning

confidence: 99%

Liquid-state carbon-13 hyperpolarization generated in an MRI system for fast imaging

et al. 2017

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Hyperpolarized (HP) tracers dramatically increase the sensitivity of magnetic resonance imaging (MRI) to monitor metabolism non-invasively and in vivo. Their production, however, requires an extra polarizing device (polarizer) whose complexity, operation and cost can exceed that of an MRI system itself. Furthermore, the lifetime of HP tracers is short and some of the enhancement is lost during transfer to the application site. Here, we present the production of HP tracers in water without an external polarizer: by Synthesis Amid the Magnet Bore, A Dramatically Enhanced Nuclear Alignment (SAMBADENA) is achieved within seconds, corresponding to a hyperpolarization of ∼20%. As transfer of the tracer is no longer required, SAMBADENA may permit a higher polarization at the time of detection at a fraction of the cost and complexity of external polarizers. This development is particularly promising in light of the recently extended portfolio of biomedically relevant para-hydrogen-tracers and may lead to new diagnostic applications.

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“…Furthermore, SABRE occurs in the liquid state at room temperature and requires only inexpensive equipment. 21,26,27 As depicted in Scheme 1, SABRE uses a transition metal catalyst to establish contact between the polarization source, para -H 2 , and the target nuclei.…”

Section: Introductionmentioning

confidence: 99%

Generalizing, Extending, and Maximizing Nitrogen-15 Hyperpolarization Induced by Parahydrogen in Reversible Exchange

et al. 2017

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Signal Amplification by Reversible Exchange (SABRE) is a fast and convenient NMR hyperpolarization method that uses cheap and readily available para-hydrogen as a hyperpolarization source. SABRE can hyperpolarize protons and heteronuclei. Here we focus on the heteronuclear variant introduced as SABRE-SHEATH (SABRE in SHield Enables Alignment Transfer to Heteronuclei) and nitrogen-15 targets in particular. We show that 15N-SABRE works more efficiently and on a wider range of substrates than 1H-SABRE, greatly generalizing the SABRE approach. In addition, we show that nitrogen-15 offers significantly extended T1 times of up to 12 minutes. Long T1 times enable higher hyperpolarization levels but also hold the promise of hyperpolarized molecular imaging for several tens of minutes. Detailed characterization and optimization are presented, leading to nitrogen-15 polarization levels in excess of 10% on several compounds.

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Continuous Re‐hyperpolarization of Nuclear Spins Using Parahydrogen: Theory and Experiment

Cited by 48 publications

References 57 publications

NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells

NRK1 controls nicotinamide mononucleotide and nicotinamide riboside metabolism in mammalian cells

Liquid-state carbon-13 hyperpolarization generated in an MRI system for fast imaging

Generalizing, Extending, and Maximizing Nitrogen-15 Hyperpolarization Induced by Parahydrogen in Reversible Exchange

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