Aqueous Ligand-Stabilized Palladium Nanoparticle Catalysts for Parahydrogen-Induced 13C Hyperpolarization

Jeffrey McCormick; Alexander M Grunfeld; Yavuz N Ertas; Akash N Biswas; Kristofer L Marsh; Shawn Wagner; Stefan Glöggler; Louis-S Bouchard

doi:10.1021/acs.analchem.7b01363

Aqueous Ligand-Stabilized Palladium Nanoparticle Catalysts for Parahydrogen-Induced ¹³C Hyperpolarization

Anal Chem. 2017 Jul 5;89(13):7190-7194. doi: 10.1021/acs.analchem.7b01363. Epub 2017 Jun 20.

Authors

Jeffrey McCormick^{1

2}, Alexander M Grunfeld¹, Yavuz N Ertas^{2

3}, Akash N Biswas¹, Kristofer L Marsh¹, Shawn Wagner⁴, Stefan Glöggler^{1

5

6}, Louis-S Bouchard^{1

2

3}

Affiliations

¹ Department of Chemistry and Biochemistry, University of California at Los Angeles , 607 Charles E Young Drive East, Los Angeles, California 90095-1569, United States.
² The Molecular Biology Institute, Jonsson Comprehensive Cancer Center, California NanoSystems Institute (CNSI), University of California Los Angeles , Los Angeles, California 90095, United States.
³ Department of Bioengineering, University of California at Los Angeles , 420 Westwood Plaza, Los Angeles, California 90095, United States.
⁴ Biomedical Imaging Research Institute, Cedars Sinai Medical Center , 8700 Beverly Boulevard, Davis Building G149E, Los Angeles, California 90048, United States.
⁵ Max Planck Institute for Biophysical Chemistry , Am Fassberg 11, D-37077 Göttingen, Germany.
⁶ Center for Biostructural Imaging of Neurodegeneration , Von-Siebold-Straße 3A, D-37075 Göttingen, Germany.

PMID: 28590115
DOI: 10.1021/acs.analchem.7b01363

Abstract

Parahydrogen-induced polarization (PHIP) is a method for enhancing NMR sensitivity. The pairwise addition of parahydrogen in aqueous media by heterogeneous catalysts can lead to applications in chemical and biological systems. Polarization enhancement can be transferred from ¹H to ¹³C for longer lifetimes by using zero field cycling. In this work, water-dispersible N-acetylcysteine- and l-cysteine-stabilized palladium nanoparticles are introduced, and carbon polarizations up to 2 orders of magnitude higher than in previous aqueous heterogeneous PHIP systems are presented. P_¹³C values of 1.2 and 0.2% are achieved for the formation of hydroxyethyl propionate from hydroxyethyl acrylate and ethyl acetate from vinyl acetate, respectively. Both nanoparticle systems are easily synthesized in open air, and TEM indicates an average size of 2.4 ± 0.6 nm for NAC@Pd and 2.5 ± 0.8 nm for LCys@Pd nanoparticles with 40 and 25% ligand coverage determined by thermogravimetric analysis, respectively. As a step toward biological relevance, results are presented for the unprotected amino acid allylglycine upon aqueous hydrogenation of propargylglycine.

Publication types

Research Support, Non-U.S. Gov't