TY - JOUR
T1 - Reactions of methyl, hydroxyl and peroxyl radicals with the DOTA chelating agent used in medical imaging
AU - Avraham, Elad
AU - Meyerstein, Dan
AU - Lerner, Ana
AU - Yardeni, Guy
AU - Pevzner, Svetlana
AU - Zilbermann, Israel
AU - Moisy, Philippe
AU - Maimon, Eric
AU - Popivker, Inna
N1 - Publisher Copyright: © 2022 Elsevier Inc.
PY - 2022/2/20
Y1 - 2022/2/20
N2 - The mechanism of reaction of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) with ·CH3, CH3O2· and ·OH radicals were studied. The radicals were formed in situ radiolytically. The methyl radicals react orders of magnitude slower with DOTA and with MIII(DOTA)- than the hydroxyl radicals. The various final products were identified and mechanisms for their formation are proposed. CH3O2· radicals do not react, or react too slowly to be observed, with DOTA and with MIII(DOTA)- as long as the central cation is not oxidized by the peroxyl radical. The results imply that synthesis of the MIII(DOTA)-(MIII = radioisotope) complexes in a water-organic solvent (ethanol or 2-propanol or acetonitrile) mixture is not only kinetically desired but the so formed complex also decreases the radiolytic decomposition of DOTA.
AB - The mechanism of reaction of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) with ·CH3, CH3O2· and ·OH radicals were studied. The radicals were formed in situ radiolytically. The methyl radicals react orders of magnitude slower with DOTA and with MIII(DOTA)- than the hydroxyl radicals. The various final products were identified and mechanisms for their formation are proposed. CH3O2· radicals do not react, or react too slowly to be observed, with DOTA and with MIII(DOTA)- as long as the central cation is not oxidized by the peroxyl radical. The results imply that synthesis of the MIII(DOTA)-(MIII = radioisotope) complexes in a water-organic solvent (ethanol or 2-propanol or acetonitrile) mixture is not only kinetically desired but the so formed complex also decreases the radiolytic decomposition of DOTA.
UR - http://www.scopus.com/inward/record.url?scp=85123000483&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.freeradbiomed.2021.12.313
DO - https://doi.org/10.1016/j.freeradbiomed.2021.12.313
M3 - Article
C2 - 34973364
SN - 0891-5849
VL - 180
SP - 134
EP - 142
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
ER -