Influence of Calcium-Induced Aggregation on the Sensitivity of Aminobis(methylenephosphonate)-Containing Potential MRI Contrast Agents
作者:Jörg Henig、Ilgar Mamedov、Petra Fouskova、Éva Tóth、Nikos K. Logothetis、Goran Angelovski、Hermann A. Mayer
DOI:10.1021/ic1024235
日期:2011.7.18
A novel class of 1,4,7,10-tetraazacyclododecane-1,4,7-tris(methylenecarboxylic) acid (DO3A)-based lanthanide complexes with relaxometric response to Ca2+ was synthesized, and their physicochemical properties were investigated. Four macrocyclic ligands containing an alkyl-aminobis(methylenephosphonate) side chain for Ca2+-chelation have been studied (alkyl is propyl, butyl, pentyl, and hexyl for L1
合成了一类新型的1,4,7,10-四氮杂十二烷-1,4,7-三(亚甲基羧酸)(DO3A)基镧系配合物,其对Ca 2+具有弛豫响应,并对其理化性质进行了研究。已经研究了四个含有用于Ca 2+螯合的烷基-氨基双(亚甲基膦酸酯)侧链的大环配体(对于L 1,L 2,L 3和L 4,烷基分别为丙基,丁基,戊基和己基)。添加Ca 2+时,其Gd 3+的r 1弛豫性最好的化合物GdL 3和GdL 4的配合物降低了初始值的61%。配合物的弛豫度与浓度有关(随浓度的增加而降低)。对Y 3+类似物的扩散NMR研究表明,在较高浓度下会形成附聚物。在Ca 2+存在下,聚集变得更加重要。EuL 1和EuL 4的31 P NMR实验表明膦酸酯与Ln 3+的配位对于具有丙基链的配体,没有观察到膦酸酯配位。电位滴定产生Gd 3+配合物的质子化常数。所有复合物的log K H1值在6.12和7.11之间,而log K H2值在4