Fine optimization of a dissolution dynamic nuclear polarization experimental setting for C NMR of metabolic samples.

NMR-based analysis of metabolite mixtures provides crucial information on biological systems but mostly relies on 1D H experiments for maximizing sensitivity. However, strong peak overlap of H spectra often is a limitation for the analysis of inherently complex biological mixtures. Dissolution dynamic nuclear polarization (d-DNP) improves NMR sensitivity by several orders of magnitude, which enables C NMR-based analysis of metabolites at natural abundance.

Porous functionalized polymers enable generating and transporting hyperpolarized mixtures of metabolites.

Hyperpolarization by dissolution dynamic nuclear polarization (dDNP) has enabled promising applications in spectroscopy and imaging, but remains poorly widespread due to experimental complexity. Broad democratization of dDNP could be realized by remote preparation and distribution of hyperpolarized samples from dedicated facilities. Here we show the synthesis of hyperpolarizing polymers (HYPOPs) that can generate radical- and contaminant-free hyperpolarized samples within minutes with lifetimes exceeding hours in the solid state.

Pulse sequence and sample formulation optimization for dipolar order mediated H→C cross-polarization.

We have recently demonstrated the use of contactless radiofrequency pulse sequences under dissolution-dynamic nuclear polarization conditions as an attractive way of transferring polarization from sensitive 1H spins to insensitive 13C spins with low peak radiofrequency pulse powers and energies via a reservoir of dipolar order. However, many factors remain to be investigated and optimized to enable the full potential of this polarization transfer process. We demonstrate herein the optimization of several key factors by: (i) implementing more efficient shaped radiofrequency pulses; (ii) adapting 13C spin labelling; and (iii) avoiding methyl group relaxation sinks.

Hyperpolarized NMR Metabolomics at Natural C Abundance.

Metabolomics plays a pivotal role in systems biology, and NMR is a central tool with high precision and exceptional resolution of chemical information. Most NMR metabolomic studies are based on H 1D spectroscopy, severely limited by peak overlap. C NMR benefits from a larger signal dispersion but is barely used in metabolomics due to ca.

Dissolution dynamic nuclear polarization of deuterated molecules enhanced by cross-polarization.

We present novel means to hyperpolarize deuterium nuclei in CD groups at cryogenic temperatures. The method is based on cross-polarization from H to C and does not require any radio-frequency fields applied to the deuterium nuclei. After rapid dissolution, a new class of long-lived spin states can be detected indirectly by C NMR in solution.