Stabilities of the alkaline earth and divalent transition metal complexes of the tetraazamacrocyclic tetraacetic acid ligands

Radiolabeling and biological evaluation of DOTA-Ph-Al derivative conjugated to anti-EGFR antibody ior egf/r3 for targeted tumor imaging and therapy

“…111 In and therapeutic radionuclide like 90 Y, which does not bind non specifically to biological system, the only chelator known to form stable complexes is DOTA and its derivatives with excellent radiophysical properties have been well characterized. [14][15][16][17][18][19][20][21]29,31 The thermodynamic stability of bifunctional DOTA is not unusual but a convenient synthetic approach to produce readily available bifunctional DOTA to be conjugated to the protein molecule is highlighted in the present work. Linkage to the one of the carboxylate of the DOTA provided shorter synthetic route and the macrocyclic framework is well organized giving thermodynamic and kinetic stability.…”

“…Derivatives of DOTA constituted a promising class of chelating agents for radiotherapy because they form extremely stable and inert complexes with a wide variety of metal anion. [15][16][17][18][19][20] We have developed convenient route of synthesis based on DOTA-BA in which the coordination chemistry is well defined. 21 This paper presents the successful synthesis of a new derivative of DOTA with a single amino acid phenylalanine linker to facilitate fast clearance of radioactive drug from blood and reduce the radiation exposure to the normal tissue and its conjugation with anti EGFR antibody ior egf/r3.…”

Critical Evaluation of Stability Constants of Metal Complexes of Complexones for Biomedical and Environmental Applications (IUPAC Technical Report)

“…Thus, the purity of the compounds used by some authors is not sufficient for accurate equilibrium constant determinations. For this reason, all the data obtained by [91CMa] and [91CMb] for DOTA were discarded. The separation of inorganic salts resulting from the synthesis of NOTA or DOTA can be made by ionic exchange chromatography, however, several authors do not perform this step.…”

“…The data published for 25 °C and 0.1 mol L -1 KNO 3 (lg K ML = 13.4; lg K(BeL + H) = 5.12) are considered reliable, but for critical evaluation an independent measurement is required. The Mg 2+ complex presents a very low stability constant, but it is impossible to recommend a value owing to the large difference between the values reported [91CMa,82DSa].…”

{Ca(OH2)3[Ca(DOTA)].7.7H2O}n

“…The DOTA ligand (1,4,7,10-tetraazacyclododecane-N,N',N',N"-tetraacetate) (Clarke & Martell, 1991). This seems rather unusual when one considers that the Ca" metal must bind to four N atoms in the DOTA ligand to fully utilize the octadentate coordination.…”