Hyperpolarising Pyruvate through Signal Amplification by Reversible Exchange (SABRE)

Abstract

Hyperpolarisation methods that premagnetise agents such as pyruvate are currently receiving significant attention because they produce sensitivity gains that allow disease tracking and interrogation of cellular metabolism by magnetic resonance. Here, we communicate how signal amplification by reversible exchange (SABRE) can provide strong ¹³ C pyruvate signal enhancements in seconds through the formation of the novel polarisation transfer catalyst [Ir(H)₂ (η² -pyruvate)(DMSO)(IMes)]. By harnessing SABRE, strong signals for [1-¹³ C]- and [2-¹³ C]pyruvate in addition to a long-lived singlet state in the [1,2-¹³ C₂ ] form are readily created; the latter can be observed five minutes after the initial hyperpolarisation step. We also demonstrate how this development may help with future studies of chemical reactivity.

Keywords: SABRE; catalysis; hyperpolarization; pyruvate; singlet state.