Abstract
Free radicals generated by UV-light irradiation of a frozen solution containing a fraction of pyruvic acid (PA) have demonstrated their dissolution dynamic nuclear polarization (dDNP) potential, providing up to 30 % [1-(13) C]PA liquid-state polarization. Moreover, their labile nature has proven to pave a way to nuclear polarization storage and transport. Herein, differently from the case of PA, the issue of providing dDNP UV-radical precursors (trimethylpyruvic acid and its methyl-deuterated form) not involved in any metabolic pathway was investigated. The (13) C dDNP performance was evaluated for hyperpolarization of [U-(13) C(6) ,1,2,3,4,5,6,6-d(7) ]-d-glucose. The generated UV-radicals proved to be versatile and highly efficient polarizing agents, providing, after dissolution and transfer (10 s), a (13) C liquid-state polarization of up to 32 %.