Nuclear magnetic resonance (NMR) is widely used as a structural analysis technique for organic matter in various fields. However, NMR has the limitation of low detection limits. Consequently, researchers are actively exploring hyperpolarization techniques to enhance the NMR signal. One promising method is Signal Amplification by Reversible Exchange (SABRE), which utilizes para-hydrogen. SABRE offers the advantage of obtaining amplified NMR signals directly from the substrate itself, without altering its structure, while enabling continuous signal amplification. This study aims to investigate the potential of SABRE for signal amplification, with a particular focus on its application in magnetic resonance imaging (MRI) based on the principles of NMR.
SABRE experiments were conducted on essential amino acids, which are the fundamental building blocks of the body's proteins. These experiments specifically focused on the L-amino acids. So, investigations were carried out to explore potential differences based on stereochemistry, specifically targeting the D-form. As a result, a difference in signal amplification was observed between the D and L forms, specifically in the case of tryptophan and leucine. These findings provide valuable insights and lay the foundation for further research on the application of Sabre experiments to biomedicine.