Heat-bath cooling of spins in two amino acids

► We apply heat-bath cooling, part of algorithmic cooling of spins, to amino acids. ► For labeled glutamate and glycine both 13C polarizations were enhanced by ∼2.5-fold. ► The total entropy of each spin system is shown to decrease after elementary cooling. ► Similar results obtained with Magnevist and at physiological temperature. ► Heat-bath cooling is applicable in vivo for 13C magnetic resonance spectroscopy.