Parawasserstoff‐induzierte Polarisation von Aminosäuren

Pravdivtsev, Andrey N.; Buntkowsky, Gerd; Duckett, Simon B.; Koptyug, Igor V.; Hövener, Jan‐Bernd

doi:10.1002/ange.202100109

“…This restriction, however, was mitigated by adding an unsaturated side group (unsaturated auxiliary group, UAG) to the desired contrast agents. [27][28][29] After hydrogenation of the side group and polarization transfer to the main molecule, the auxiliary group was cleaved and the desired contrast agents resulted.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and hyperpolarization of 13C and 2H labeled vinyl pyruvate and pyruvate

Herges

¹

,

Brahms

²

,

Pravdivtsev

³

et al. 2022

Preprint

0

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The hyperpolarization of nuclear spins has enabled unique applications in chemistry, biophysics, and particularly in metabolic imaging. Parahydrogen-induced polarization (PHIP) offers a fast and cost-efficient way of hyperpolarization. Nevertheless, PHIP lags behind dynamic nuclear polarization (DNP), which is already being evaluated in clinical studies. This shortcoming is mainly due to problems in the synthesis of the corresponding PHIP precursor molecules. The most widely used DNP tracer in clinical studies, particularly for the detection of prostate cancer, is 1-13C-pyruvate. The ideal derivative for PHIP is the deuterated vinyl ester because the spin physics allows for 100% polarization. Unfortunately, there is no efficient synthesis for vinyl esters of -ketocarboxylic acids in general and pyruvate in particular. Here, we present an efficient new method for the preparation of vinyl esters, including 13C labeled, fully deuterated vinyl pyruvate using a palladium catalyzed procedure. Using 50 % enriched parahydrogen and mild reaction conditions, a 13C polarization of 12% was readily achieved; 36% are expected with 100% pH2. Higher polarization values can be potentially achieved with optimized reaction conditions.

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“…[12,13] Despite these achievements with DNP,c heaper and instrumentally less demanding hyperpolarization techniques would be of great interest to transform such proof of principles into realcase implementations.T his has motivated al arge number of recent studies utilizing PHIP to hyperpolarize amino acids. [14] Amino acids have mainly been hyperpolarized with hydrogenative PHIP. [3,4] Since this technique relies on the hydrogenation of asubstrate with parahydrogen (p-H 2 ), only unsaturated molecules can be hyperpolarized.…”

Section: Introductionmentioning

confidence: 99%

Parahydrogen Hyperpolarization Allows Direct NMR Detection of α‐Amino Acids in Complex (Bio)mixtures

Sellies¹,

Aspers²,

Feiters³

et al. 2021

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The scope of non-hydrogenative parahydrogen hyperpolarization (nhPHIP) techniques has been expanding over the last years,w ith the continuous addition of important classes of substrates.F or example,p yruvate can nowb e hyperpolarized using the Signal Amplification By Reversible Exchange (SABRE) technique,o ffering af ast, efficient and low-cost PHIP alternative to Dynamic Nuclear Polarization for metabolic imaging studies.S till, important biomolecules such as amino acids have so far resisted PHIP,unless properly functionalized. Here,wereport on an approach to nhPHIP for unmodified a-amino acids that allows their detection and quantification in complex mixtures at sub-micromolar concentrations.This method was tested on human urine,inwhich natural a-amino acids could be measured after dilution with methanol without any additional sample treatment.

show abstract

Parahydrogen Hyperpolarization Allows Direct NMR Detection of α‐Amino Acids in Complex (Bio)mixtures

Sellies¹,

Aspers²,

Feiters³

et al. 2021

View full text Add to dashboard Cite

The scope of non-hydrogenative parahydrogen hyperpolarization (nhPHIP) techniques has been expanding over the last years,w ith the continuous addition of important classes of substrates.F or example,p yruvate can nowb e hyperpolarized using the Signal Amplification By Reversible Exchange (SABRE) technique,o ffering af ast, efficient and low-cost PHIP alternative to Dynamic Nuclear Polarization for metabolic imaging studies.S till, important biomolecules such as amino acids have so far resisted PHIP,unless properly functionalized. Here,wereport on an approach to nhPHIP for unmodified a-amino acids that allows their detection and quantification in complex mixtures at sub-micromolar concentrations.This method was tested on human urine,inwhich natural a-amino acids could be measured after dilution with methanol without any additional sample treatment.

show abstract

Parawasserstoff‐induzierte Polarisation von Aminosäuren

Cited by 3 publications

References 126 publications

Synthesis and hyperpolarization of 13C and 2H labeled vinyl pyruvate and pyruvate

Synthesis and hyperpolarization of 13C and 2H labeled vinyl pyruvate and pyruvate

Parahydrogen Hyperpolarization Allows Direct NMR Detection of α‐Amino Acids in Complex (Bio)mixtures

Parahydrogen Hyperpolarization Allows Direct NMR Detection of α‐Amino Acids in Complex (Bio)mixtures

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