Parahydrogen-induced polarization of amino acids

Nuclear magnetic resonance (NMR) has become a universal method for biochemical and biomedical studies, including metabolomics, proteomics and magnetic resonance imaging (MRI). By increasing the signal of selected molecules, the hyperpolarization of nuclear spins has expanded the reach of NMR and MRI even further (e.g. hyperpolarized solid-state NMR and metabolic imaging in vivo). Parahydrogen (pH2) offers a fast and cost-efficient way to achieve hyperpolarization, and the last decade has seen extensive advances including the synthesis of new tracers, catalysts, and transfer methods. The portfolio of hyperpolarized molecules now includes amino acids, which are of great interest for many applications. Here, we review the current literature and developments for the hyperpolarization of amino acids and peptides.