Francesca Reineri1, Alessandra Viale1, Silvano Ellena1, Tommaso Boi1, Roberto Gobetto1, Silvio Aime1
1University of Torino, Torino, IT, Italy
Para-Hydrogen Induced Polarization (PHIP) has been recently exploited for the preparation of hyperpolarized 13C contrast agents for MRI. For the observation of large PHIP effects the use of homogeneous hydrogenation catalysts is generally required. The catalyst and (if present) the organic solvent must then be removed in order to obtain non-toxic formulations of the hyperpolarized agents. Here we report the para-hydrogenation of an unsaturated activated substrate, maleic anhydride, in chloroform, followed by rapid hydrolysis to form a water-soluble derivative, succinic acid, which can be extracted in water to yield a pure aqueous solution of the hyperpolarized molecule.