13C hyperpolarized spectra of TFPP in aqueous solutions acquired with 10° excitation pulse at 35–40°C: a) 6 mM TFPP, 4.5 M ethanol (EtOH), b) 2 mM TFPP, 1.5 M EtOH, 20 mM DMPC, c) 2 mM TFPP, 1.8 M EtOH in 60% porcine blood. 13C T1 value shown for each resonance was measured by recording 13C hyperpolarized signal decay with small angle excitation pulses.