TY - JOUR
T1 - New hyperpolarized contrast agents for 13C-MRI from para-hydrogenation of oligooxyethylenic alkynes
AU - Reineri, Francesca
AU - Viale, Alessandra
AU - Giovenzana, Giovanbattista
AU - Santelia, Daniela
AU - Dastrù, Walter
AU - Gobetto, Roberto
AU - Aime, Silvio
PY - 2008/11/12
Y1 - 2008/11/12
N2 - Two alkyne derivatives, which contain one and two oligooxyethylenic chains respectively, showed to be good substrates for para-hydrogenation reactions, yielding the corresponding hyperpolarized alkenes in good yields. A suitable theory has been developed to account for the observed results, fully explaining the different para-H2 induced effects observed upon the para-hydrogenation of symmetrically and asymmetrically substituted alkynes in ALTADENA and PASADENA modes. The oligooxyethylenic substituent provides good water solubility to the para-hydrogenated symmetrical derivative. 13C-MR in vitro images of the latter derivative were obtained both in acetone and in water solutions (130 mM), using the ALTADENA procedure and after application of the field cycling procedure which allows acquisition of an in-phase 13C carbonyl resonance. The finding that the hydrogenated product is water-soluble in contrast to the parent alkyne which is not allows for the pursuit of a fast phase-transfer separation from the organic solvent, the unreacted substrate, and the catalyst to obtain a "ready-to-use" water solution suitable for further in vivo MRI applications.
AB - Two alkyne derivatives, which contain one and two oligooxyethylenic chains respectively, showed to be good substrates for para-hydrogenation reactions, yielding the corresponding hyperpolarized alkenes in good yields. A suitable theory has been developed to account for the observed results, fully explaining the different para-H2 induced effects observed upon the para-hydrogenation of symmetrically and asymmetrically substituted alkynes in ALTADENA and PASADENA modes. The oligooxyethylenic substituent provides good water solubility to the para-hydrogenated symmetrical derivative. 13C-MR in vitro images of the latter derivative were obtained both in acetone and in water solutions (130 mM), using the ALTADENA procedure and after application of the field cycling procedure which allows acquisition of an in-phase 13C carbonyl resonance. The finding that the hydrogenated product is water-soluble in contrast to the parent alkyne which is not allows for the pursuit of a fast phase-transfer separation from the organic solvent, the unreacted substrate, and the catalyst to obtain a "ready-to-use" water solution suitable for further in vivo MRI applications.
UR - http://www.scopus.com/inward/record.url?scp=57349183131&partnerID=8YFLogxK
U2 - 10.1021/ja8059733
DO - 10.1021/ja8059733
M3 - Article
SN - 0002-7863
VL - 130
SP - 15047
EP - 15053
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 45
ER -