Hyperpolarization of Amino Acids in Water Utilizing Parahydrogen on a Rhodium Nanocatalyst

Abstract

NMR offers many possibilitiesi nc hemical analysis, structurali nvestigations, and medical diagnostics. Although it is broadly used, one of NMR spectroscopies main drawbacks is low sensitivity.H yperpolarization techniques enhanceN MR signals by more than four orders of magnitude allowing the design of new contrast agents. Parahydrogen induced polarization that utilizes the parahydrogen's singlet state to create enhanced signals is of particular interests ince it allows to producem olecular imagingagentswithin seconds. Herein,wepresent astrategy for signal enhancement of the carbonyl 13 Ci na mino acids by using parahydrogen,a sd emonstratedf or glycine and alanine. Importantly,t he hyperpolarizations tep is carried out in water and chemically unmodifiedc anonical amino acids are obtained. Our approach thus offers ah igh degree of biocompatibility,w hich is crucial for furthera pplication. The rapid sample hyperpolarization (withins econds) may enable the continuous productiono fb iologically useful probes, such as metabolic contrast agents or probes for structuralbiology.[e] Prof. Dr.M.U tz SchoolofC hemistry,University of Southampton SouthamptonS O171BJ (UK)Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.

Pd-based bimetallic catalysts for parahydrogen-induced polarization in heterogeneous hydrogenations

“…This, however, does not exhaust the list of activities that would benefit from the facile production/enrichment of NSIMs of polyatomic molecules. In modern science, of significant interest are the properties of NSIMs, including their interconversion processes (Chapovsky and Hermans, 1999) and NSIM behavior upon phase transitions (Curl et al, 1966;Hama et al, 2018); the NSIM-related selection rules in molecular spectroscopy (Kanamori et al, 2017;Ozier et al, 1970) and upon chemical transformations (Hu et al, 2020;Kilaj et al, 2018;Oka, 2004); NSIMs in astrophysics and astrochemistry research (Hama and Watanabe, 2013;Hily-Blant et al, 2018;Shinnaka et al, 2016;Tielens, 2013); and more.…”

Catalytic Hydrogenation of Trivinyl Orthoacetate: Mechanisms Elucidated by Parahydrogen Induced Polarization

“…Here, a side arm is hydrogenated and then polarization is transferred to the target site of the polarized molecule, which often is the 13 C nucleus of a carboxyl group. PHIP‐SAH has enabled hyperpolarization of a larger number of endogenous molecules including acetate (Figure 1a), pyruvate, [30] amino acids [31] and peptides [32] …”

Heterogeneous 1H and 13C Parahydrogen‐Induced Polarization of Acetate and Pyruvate Esters

“…Ligand‐capped Pd and Rh nanoparticles provided higher 13 C polarization levels of up to 1.3 % for ethyl [1‐ 13 C]acetate, but at the expense of lower chemical conversion of the reactant vinyl [1‐ 13 C]acetate to reaction product [33,73] . Also heterogeneous PHIP‐SAH approach was utilized to produce 13 C HP amino acids with P 13C =0.29 % after side arm cleavage [74] …”