Fig. 2.

Hyperpolarized [1-¹³C]-acetate, [1-¹³C]-pyruvate, l-alanine-glycine, and fumarate. Thermal equilibrium and hyperpolarized signals of (A) [1-¹³C]-acetate, (B) [1-¹³C]-pyruvate, and (C) l-alanine-glycine and fumarate. Hyperpolarization was performed as described in the text by ¹H→¹³C CP-DNP with HYPSO 1.0 followed by dissolution. The hyperpolarized signals were acquired with single 5° nutation angle pulses, whereas the thermal equilibrium signals, scaled by a factor of 5,000, were measured with 27, 128, and 512 scans for [1-¹³C]-acetate, [1-¹³C]-pyruvate, and l-alanine-glycine and fumarate, respectively, using 90° nutation angle pulses applied every 300 s.