Carbon‐13 Hyperpolarization of α‐Ketocarboxylates with Parahydrogen in Reversible Exchange

• DOI: 10.1002/cmdc.202400378
• Publication Date: 2024-10-04T07:11:05Z
• Authors: Stephen J. McBride; Keilian MacCulloch; Patrick TomHon; Austin Browning; Samantha Meisel; Mustapha Abdulmojeed; Boyd M. Goodson; Eduard Y. Chekmenev; Thomas Theis
• Keywords: Hyperpolarization; Carboxylate

Signal Amplification by Reversible Exchange (SABRE) is a relatively simple and fast hyperpolarization technique that has been used to hyperpolarize the α‐ketocarboxylate pyruvate, central metabolite leading hyperpolarized MRI contrast agent. In this work, we show SABRE can readily be extended 13C nuclei at natural abundance on many other α‐ketocarboxylates. Hyperpolarization observed optimized pyruvate (P13C=17%) 2‐oxobutyrate (P13C=25%) with alkyl chains in R‐group, oxaloacetate (P13C=11%) alpha‐ketoglutarate (P13C=13%) carboxylate moieties R group, phenylpyruvate (P13C=2%) phenylglyoxylate phenyl rings R‐group. New catalytically active binding motifs of substrates transfer catalyst—particularly for oxaloacetate—are observed. We experimentally explore connection between temperature exchange rates all these systems develop theoretical kinetic model, which fit build‐up decay during activity.