Rational design of [13C,D14]tert-butylbenzene as a scaffold structure for designing long-lived hyperpolarized 13C probes

Dynamic nuclear polarization (DNP) is a technique to polarize the nuclear spin population. As a result of the hyperpolarization, NMR sensitivity of the nuclei in molecules can be enhanced dramatically. Recent application of the hyperpolarization technique has led to advances in biochemical and molecular studies. A major problem is the short lifetime of the polarized nuclear spin state. Generally, in solution, the polarized nuclear spin state decays to a thermal spin equilibrium, resulting in loss of the enhanced NMR signal. This decay is correlated directly with the spin-lattice relaxation time T1. Here we report [13C,D14]tert-butylbenzene as a new scaffold structure for designing hyperpolarized 13C probes. Thanks to the minimized spin-lattice relaxation (T1) pathways, its water-soluble derivative showed a remarkably long 13C T1 value and long retention of the hyperpolarized spin state