Hyperpolarizing Small Molecules using Parahydrogen and Solid-State Spin Diffusion.

Parahydrogen-induced polarization (PHIP) is an inexpensive way to produce hyperpolarized molecules with polarization levels of >10 % in the solution-state, but is strongly limited in generality since it requires chemical reactions/ interactions with H. Here we report a new method to widen the scope of PHIP hyperpolarization: a source molecule is produced via PHIP with high C polarization, and precipitated out of solution together with a target species. Spin diffusion within the solid carries the polarization onto C spins of the target, which can then be dissolved for solution-state applications.

Solution-State 2D NMR Spectroscopy of Mixtures HyperpolarizedUsing Optically Polarized Crystals.

The HYPNOESYS method (Hyperpolarized NOE System), which relies on the dissolution of optically polarized crystals, has recently emerged as a promising approach to enhance the sensitivity of NMR spectroscopy in the solution state. However, HYPNOESYS is a single-shot method that is not generally compatible with multidimensional NMR. Here we show that 2D NMR spectra can be obtained from HYPNOESYS-polarized samples, using single-scan acquisition methods.

Parahydrogen-Polarized [1- C]Pyruvate for Reliable and Fast Preclinical Metabolic Magnetic Resonance Imaging.

Hyperpolarization techniques increase nuclear spin polarization by more than four orders of magnitude, enabling metabolic MRI. Even though hyperpolarization has shown clear value in clinical studies, the complexity, cost and slowness of current equipment limits its widespread use. Here, a polarization procedure of [1- C]pyruvate based on parahydrogen-induced polarization by side-arm hydrogenation (PHIP-SAH) in an automated polarizer is demonstrated.

Parahydrogen-Polarized Fumarate for Preclinical Metabolic Magnetic Resonance Imaging.

We present a versatile method for the preparation of hyperpolarized [1-C]fumarate as a contrast agent for preclinical MRI, using parahydrogen-induced polarization (PHIP). To benchmark this process, we compared a prototype PHIP polarizer to a state-of-the-art dissolution dynamic nuclear polarization (d-DNP) system. We found comparable polarization, volume, and concentration levels of the prepared solutions, while the preparation effort is significantly lower for the PHIP process, which can provide a preclinical dose every 10 min, opposed to around 90 min for d-DNP systems.

Hyperpolarized Solution-State NMR Spectroscopy with Optically Polarized Crystals.

Nuclear spin hyperpolarization provides a promising route to overcome the challenges imposed by the limited sensitivity of nuclear magnetic resonance. Here we demonstrate that dissolution of spin-polarized pentacene-doped naphthalene crystals enables transfer of polarization to target molecules via intermolecular cross-relaxation at room temperature and moderate magnetic fields (1.45 T).