0000000000173097
AUTHOR
Imre Tóth
Equilibrium, Kinetic and Structural Properties of Gallium(III) and Some Divalent Metal Complexes Formed with the New DATAm and DATA5m Ligands
The development of 68Ge/68Ga generators has made the positron-emitting 68Ga isotope widely accessible and raised interest in new chelate complexes of Ga3+. The hexadentate 1,4-di(acetate)-6-methyl[amino(methyl)acetate]perhydro-1,4-diazepane (DATAm) ligand and its bifunctional analogue, 1,4-di(acetate)-6-pentanoic acid[amino(methyl)acetate]perhydro-1,4-diazepane (DATA5m), rapidly form complexes with 68Ga in high radiochemical yield. The stability constants of DATAm and DATA5m complexes formed with Ga3+, Zn2+, Cu2+, Mn2+ and Ca2+ have been determined by using pH potentiometry, spectrophotometry (Cu2+) and 1H and 71Ga NMR spectroscopy (Ga3+). The stability constants of Ga(DATAm) and Ga(DATA5m)…
Improved Efficacy of Synthesizing *MIII-Labeled DOTA Complexes in Binary Mixtures of Water and Organic Solvents. A Combined Radio- and Physicochemical Study
Typically, the synthesis of radiometal-based radiopharmaceuticals is performed in buffered aqueous solutions. We found that the presence of organic solvents like ethanol increased the radiolabeling yields of [68Ga]Ga-DOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacatic acid). In the present study, the effect of organic cosolvents [ethanol (EtOH), isopropyl alcohol, and acetonitrile] on the radiolabeling yields of the macrocyclic chelator DOTA with several trivalent radiometals (gallium-68, scandium-44, and lutetium-177) was systematically investigated. Various binary water (H2O)/organic solvent mixtures allowed the radiolabeling of DOTA at a significantly lower temperature than …