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Avraham E, Meyerstein D, Lerner A, Yardeni G, Pevzner S, Zilbermann I, Moisy P, Maimon E, Popivker I. Reactions of methyl, hydroxyl and peroxyl radicals with the DOTA chelating agent used in medical imaging. Free Radic Biol Med 2022; 180:134-142. [PMID: 34973364 DOI: 10.1016/j.freeradbiomed.2021.12.313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/13/2021] [Accepted: 12/27/2021] [Indexed: 12/30/2022]
Abstract
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.
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Affiliation(s)
- Elad Avraham
- Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Dan Meyerstein
- Department of Chemical Sciences, The Radical Research Center and the Schlesinger Family, Center for Compact Accelerators, Radiation Sources and Application, Ariel University, Ariel, Israel; Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ana Lerner
- Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Israel Atomic Energy Commission, Tel Aviv, Israel
| | - Guy Yardeni
- Chemistry Department, Nuclear Research Centre Negev, Beer-Sheva, Israel
| | - Svetlana Pevzner
- Chemistry Department, Nuclear Research Centre Negev, Beer-Sheva, Israel
| | - Israel Zilbermann
- Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Chemistry Department, Nuclear Research Centre Negev, Beer-Sheva, Israel
| | - Philippe Moisy
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France
| | - Eric Maimon
- Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Chemistry Department, Nuclear Research Centre Negev, Beer-Sheva, Israel
| | - Inna Popivker
- Chemistry Department, Nuclear Research Centre Negev, Beer-Sheva, Israel.
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