Gadolinium complexes of macrocyclic diethylenetriamine-<i>N</i>-oxide pentaacetic acid-bisamide as highly stable MRI contrast agents with high relaxivity
作者:Kehan Xu、Na Xu、Beibei Zhang、Weijun Tang、Yun Ding、Aiguo Hu
DOI:10.1039/d0dt00248h
日期:——
are generally considered efficient magnetic resonance imaging (MRI) contrast agents (CAs) and widely used in clinical applications. High relaxivity and stability are two essential criteria for a Gd(III)-complex to be used as a MRI-CA. One crucial strategy to achieve high relaxivity for small molecular Gd(III)-based MRI contrast agents is to increase the hydration number q. Meanwhile, metal complexes
d(III)配合物通常被认为是有效的磁共振成像(MRI)造影剂(CA),广泛用于临床。高弛豫性和稳定性是Gd(III)复合物用作MRI-CA的两个基本标准。对于基于小分子Gd(III)的MRI造影剂,实现高松弛度的一项关键策略是增加水合数q。同时,已经证明具有大环配体的金属配合物具有高的热力学稳定性和动力学惰性。在此,合成了基于二亚乙基三胺-N-氧化物五乙酸-双酰胺的一系列大环配体。其中,环-DTPA-NO-C6O2(3d实验结果证实)是Gd(III)最强的配体。通过发光测量将Gd-环-DTPA-NO-C6O2(4d)配合物的水合数定为3,并通过计算仿真确认了配位结构。因此,该复合物的弛豫性(14.3 mM -1 s -1,1.5 T,25°C)约为商业MRI CA的三倍。Gd(III的条件稳定性常数由分光光度滴定研究计算得出的复合物pGd与最稳定的商用MRI-CA之一Gd-DTPA(Ma