title: Delivering strong1H nuclear hyperpolarization levels and long magnetic lifetimes through signal amplification by reversible exchange.
abstract: Hyperpolarization turns typically weak NMR and MRI responses into strong signals so that ordinarily impractical measurements become possible. The potential to revolutionize analytical NMR and clinical diagnosis through this approach reflect this area's most compelling outcomes. Methods to optimize the low-costparahydrogen-based approach signal amplification by reversible exchange with studies on a series of biologically relevant nicotinamides and methyl nicotinates are detailed. These procedures involve specific2H labeling in both the agent and catalyst and achieve polarization lifetimes ofca2 min with 50% polarization in the case of methyl-4,6-d2-nicotinate. Because a 1.5-T hospital scanner has an effective1H polarization level of just 0.0005% this strategy should result in compressed detection times for chemically discerning measurements that probe disease. To demonstrate this technique's generality, we exemplify further studies on a range of pyridazine, pyrimidine, pyrazine, and isonicotinamide analogs that feature as building blocks in biochemistry and many disease-treating drugs.
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rayner
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Burns
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Olaru
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Philip
authors.initials: P
authors.lastname: Norcott
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Marianna
authors.initials: M
authors.lastname: Fekete
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Gary G R
authors.initials: GGR
authors.lastname: Green
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Louise A R
authors.initials: LAR
authors.lastname: Highton
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom.
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Mewis
authors.affiliation: Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington YO10 5NY, United Kingdom sbd3@york.ac.uk.
authors.forename: Simon B
authors.identifier: 0000-0002-9788-6615
authors.initials: SB
authors.lastname: Duckett
keywords: MRI; NMR; SABRE; catalysis; hyperpolarization