Our Research & Other Key Publications
Catalytic Hydrogenation of Trivinyl Orthoacetate: Mechanisms Elucidated by Parahydrogen Induced Polarization
A. N. Pravdivtsev, A. Brahms, S. Kienitz, F. D. Sönnichsen, J.-B. Hövener, R. Herges, ChemPhysChem 2021, 22, 370-377.
DOI: 10.1002/cphc.202000957
https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cphc.202000957
A novel tracer was synthesized to investigate the influence of multiple unsaturated compounds on hyperpolarization. Using hyperpolarization, previously hidden processes at the catalyst were made visible. This highlights the technology's potential for catalyst optimization.
Rating Relevance, 3 of 10
Selective excitation of hydrogen doubles the yield and improves the robustness of parahydrogen-induced polarization of low-γ nuclei
A. B. Schmidt, A. Brahms, F. Ellermann, S. Knecht, S. Berner, J. Henning, D. von Elverfeldt, R. Herges, J.-B. Hövener, A. N. Pravdivtsev, Phys. Chem. Chem. Phys. 2021, 23, 26645-26652.
DOI: 10.1039/D1CP04153C
https://pubs.rsc.org/en/content/articlelanding/2021/cp/d1cp04153c
A newly developed pulse sequence improved the theoretically achievable polarization of our tracer to 99.6 % while the non-deuterated form has its theoretical maximum at 19.2 % polarization. These findings clearly demonstrate the critical importance of deuteration and directly underscore the superiority of our deuterated tracer over its non-deuterated form.
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Parahydrogen-induced polarization and spin order transfer in ethyl pyruvate at high magnetic fields
A. N. Pravdivtsev, A. Brahms, F. Ellermann, T. Stamp, R. Herges, J.-B. Hövener, Sci. Rep. 2022, 12, 19361.
DOI: 10.1038/s41598-022-22347-1
https://www.nature.com/articles/s41598-022-22347-1
PHIP+ allows for significantly higher production rates of hyperpolarized pyruvate compared to d-DNP, with a theoretical polarization level of 100 % for our tracer. The polarization time of our substance was reduced to just 7 seconds while d-DNP requires approximately 2 hours for similar results. This work highlights the tremendous potential of the PHIP+ technique as a superior alternative to the already established d-DNP method.
Rating Relevance, 8 of 10
Synthesis of 13C and 2H Labeled Vinyl Pyruvate and Hyperpolarization of Pyruvate
A. Brahms, A. N. Pravdivtsev, T. Stamp, F. Ellermann, F. D. Sönnichsen, J.-B. Hövener, R. Herges, Chem. Eur. J. 2022, 28, e202201210.
DOI: 10.1002/chem.202201210
https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202201210
In this work, our tracer was synthesized for the first time using a newly developed synthesis demonstrating superior yields compared to all existing methods. Furthermore, the tracer was successfully produced in a wide variety of isotopic enrichments. This publication lays the foundation for hyperpolarized pyruvate based on our tracer molecule.
Rating Relevance, 9 of 10
Spying on parahydrogen-induced polarization transfer using a half-tesla benchtop MRI and hyperpolarized imaging enabled by automation
F. Ellermann, A. Sirbu, A. Brahms, C. Assaf, R. Herges, J.-B. Höevner, A. N. Pravdivtsev, Nat. Commun. 2023, 14, 4774.
DOI: 10.1038/s41467-023-40539-9
https://www.nature.com/articles/s41467-023-40539-9
In this key publication, an automated PHIP polarizer was developed and successfully tested using our tracer compound. We were able to fully automate smaple filling, hyperpolarization, quantification, and transfer to a mobile 0.5 T MRI scanner, allowing 60 consecutive measurements without operator intervention. This approach demonstrates the effectiveness and capability of PHIP+.
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Exceptionally Mild and High-Yielding Synthesis of Vinyl Esters of Alpha-Ketocarboxylic Acids, Including Vinyl Pyruvate, for Parahydrogen-Enhanced Metabolic Spectroscopy and Imaging
A. Brahms, A. N. Pravdivtsev, L. Thorns, F. D. Sönnichsen, J.-B. Hövener, R. Herges, J. Org. Chem. 2023, 88, 15018-15028.
DOI: 10.1021/acs.joc.3c01461
https://pubs.acs.org/doi/10.1021/acs.joc.3c01461
Building on further investigation and optimization of our synthesis, the process was successfully scaled up, significantly improving the economic viability of tracer production. Our synthesis achieves nearly 20 times higher yields compared to existing methods. This work represents an important advancement in making our tracer compound more accessible for braoder applications and is considered our key publication.
Rating Relevance, 10 of 10
Rapid in situ carbon-13 hyperpolarization and imaging of acetate and pyruvate esters without external polarizer
O. Mohiuddin, H. de Maissin, A. N. Pravdivtsev, A. Brahms, M. Herzog, L. Schröder, E. Y. Chekmenev, R. Herges, J.-B. Hövener, M. Zaitsev, D. von Elverfeldt, A. B. Schmidt, Commun. Chem. 2024, 7, 240.
DOI: 10.1038/s42004-024-01316-x
Parahydrogen-Induced Polarization Relayed via Proton Exchange
K. Them, F. Ellermann, A. N. Pravdivtsev, O. G. Salnikov, I. V. Skovpin, I. V. Koptyug, R. Herges, J.-B. Hövener, J. Am. Chem. Soc. 2021, 143, 13694-13700.
DOI: 10.1021/jacs.1c05254
Nitrogen-15 dynamic nuclear polarization of nicotinamide derivatives in biocompatible solutions
J. P. Peters, A. Brahms, V. Janicaud, M. Anikeeva, E. Peschke, F. Ellermann, A. Ferrari, D. Hellmold, J. Held-Feindt, N.-m. Kim, J. Meiser, K. Aden, R. Herges, J.-B. Hövener, A. N. Pravdivtsev, Sci. Adv. 2023, 9, eadd3643.
DOI: 10.1126/sciadv.add3643
Analysis of chemical exchange in iridium N-heterocyclic carbene complexes using heteronuclear parahydrogen-enhanced NMR
C. D. Assaf, X. Gui, O. G. Salnikov, A. Brahms, N. V. Chukanov, I. V. Skovpin, E. Y. Chekmenev, R. Herges, S. B. Duckett, I. V. Koptyug, K. Buckenmaier, R. Körber, M. Plaumann, A. A. Auer, J.-B. Hövener, A. N. Pravdivtsev, Commun. Chem. 2024, 7, 286.
DOI: 10.1038/s42004-024-01376-z
Chemically induced deceleration of nuclear spin relaxation (CIDER) preserves hyperpolarization
J. P. Peters, C. Assaf, A. Brahms, K. Them, M. Gerdsen, R. Herges, J.-B. Hövener, A. N. Pravdivtsev, Sci. Adv. 2025, 11, eadx2316.
DOI: 10.1126/sciadv.adx2316
Consensus recommendations for hyperpolarized [1-13C]pyruvate MRI multi-center human studies
S. Punwani, P. E. Z. Larson, C. Laustsen, J. VanderMeulen, J. H. Ardenkjær-Larsen, A. W. Autry, J. A. Bankson, J. Bernard, R. Bok, L. B. Bertelsen, J. Che, A. P. Chen, R. Chowdhury, A. Comment, C. H. Cunningham, D. Dang, F. A. Gallagher, A. Gaunt, Y. Gong, J. W. Gordon, A. Grimmer, J. Grist, E. S. S. Hansen, M. H. Lerche, R. L. Hesketh, J.-B. Hoevener, C.-Y. Hsieh, K. R. Keshari, S. Kozerke, T. Lanz, D. Mayer, M. McLean, J. M. Park, J. Slater, D. Tyler, J.-L. Vanderheyden, C. von Morze, F. Zaccagna, V. Zaha, D. Xu, D. Vigneron, Magn. Reson. Med. 2025, 94, 1386-1400.
DOI: 10.1002/mrm.30570
Parahydrogen-Based Hyperpolarization for Biomedicine
J.-B. Hövener, A. N. Pravdivtsev, B. Kidd, C. R. Bowers, S. Glöggler, K. V. Kovtunov, M. Plaumann, R. Katz-Brull, K. Buckenmaier, A. Jerschow, F. Reineri, T. Theis, R. V. Shchepin, S. Wagner, P. Bhattacharya, N. M. Zacharias, E. Y. Chekmenev, Angew. Chem. Int. Ed. 2018, 57, 11140-11162.
DOI: 10.1002/anie.201711842
https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201711842
ParaHydrogen Induced Polarization of 13C carboxylate resonance in acetate and pyruvate
F. Reineri, T. Boi, S. Aime, Nat. Commun. 2015, 6, 5858.
DOI: 10.1038/ncomms6858
Heteronuclear Parahydrogen-Induced Hyperpolarization via Side Arm Hydrogenation
O. G. Salnikov, N. V. Chukanov, A. N. Pravdivtsev, D. B. Burueva, S. V. Sviyazov, K. Them, J.-B. Hövener, I. V. Koptyug, ChemPhysChem 2025, 26, e202401119.
DOI: 10.1002/cphc.202401119
https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cphc.202401119