Joachim Bargon1, Rahim R. Rizi2
1Institute of Physical Chemistry, University of Bonn, Bonn, Germany; 2Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA
Phosphoenolpyruvate (PEP) represents a high-energy intermediate in both glucolysis and gluconeogenesis. This enol phosphate has a high phosphoryl-transfer potential. Therefore, hyperpolarizing PEP via ParaHydrogen Induced Polarization (PHIP) provides access to both 13C-hyperpolarized pyruvate and 31P-hyperpolarized ATP. From the latter the 31P-hyperpolarization can be transferred to other molecules that need ATP for their formation. Due to efficient relaxation, only very fast conversions qualify for this purpose. Even the PEP itself qualifies as an unsaturated precursor for parahydrogenation, but then the driving force for the phosphoryl-transfer is reduced. In plants, PEP is a precursor for the biosynthesis of the aromatic amino acids.