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001-es BibID:	BIBFORM016475
Első szerző:	Kubicek, Vojtěch
Cím:	Gallium(III) Complexes of DOTA and DOTA-Monoamide : Kinetic and Thermodynamic Studies / Vojtěch Kubíček, Jana Havlíčková, Jan Kotek, Gyula Tircsó, Petr Hermann, Éva Tóth, Ivan Lukeš
Dátum:	2010
ISSN:	0020-1669
Megjegyzések:	Given the practical advantages of the Ga-68 isotope in positron emission tomography applications, gallium complexes are gaining increasing importance in biomedical imaging. However, the strong tendency of Ga3+ to hydrolyze and the slow formation and very high stability of macrocyclic complexes altogether render Ga3+ coordination chemistry difficult and explain why stability and kinetic data on Ga3+ complexes are rather scarce. Here we report solution and solid-state studies of Ga3+ complexes formed with the macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, (DOTA)(4-), and its mono(n-butylamide) derivative, (DO3AM(Bu))(3-). Thermodynamic stability constants, log K(GaDOTA) = 26.05 and log K(GaDO3AM(Bu)) = 24.64, were determined by out-of-cell pH-potentiometric titrations. Due to the very slow formation and dissociation of the complexes, equilibration times of up to similar to 4 weeks were necessary. The kinetics of complex dissociation were followed by Ga-71 NMR under both acidic and alkaline conditions. The GaDOTA complex is significantly more inert (tau(1/2) similar to 12.2 d at pH = 0 and tau(1/2) similar to 6.2 h at pH = 10) than the GaDO3AM(Bu) analogue (tau(1/2) similar to 2.7 d at pH = 0 and tau(1/2) similar to 0.7 h at pH = 10). Nevertheless, the kinetic inertness of both chelates is extremely high and approves the application of Ga3+ complexes of such DOTA-like ligands in molecular imaging. The solid-state structure of the GaDOTA complex, crystallized from a strongly acidic solution (pH < 1), evidenced a diprotonated form with protons localized on the free carboxylate pendants.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban positron-emission-tomography metal-ion complexes lanthanide(iii) complexes structural-properties tetraaza macrocycle somatostatin analog yttrium complexes contrast agent acid stability Molekulatudomány
Megjelenés:	Inorganic Chemistry. - 49 : 23 (2010), p. 10960-10969. -
További szerzők:	Havlickova, Jana Kotek, Jan Tircsó Gyula (1977-) (vegyész, kémia tanár) Hermann, Petr Tóth Éva (1967-) (koordinációs kémia) Lukeš, Ivan
Pályázati támogatás:	TÁMOP-4.2.1/B-09/1/KONV-2010-0007 TÁMOP Bimodális kontrasztanyagok tervezése, előállítása és komplexeik fizikai-kémiai tulajdonságaik jellemzése K 69098 OTKA
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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