Europium(III) DOTA-derivatives having ketone donor pendant arms display dramatically slower water exchange.
Europium(III) DOTA-derivatives having ketone donor pendant arms display dramatically slower water exchange.
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DOI：
10.1021/ic101856d
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发表时间：
2011-03-07
影响因子：
4.6
通讯作者：
Sherry AD
中科院分区：
文献类型：
--
作者：
Green KN;Viswanathan S;Rojas-Quijano FA;Kovacs Z;Sherry AD
合成了一系列以酰胺和酮为侧臂的新型四氮杂环十二烷衍生物，并用高分辨核磁共振波谱详细研究了它们与Eu(III)的配合物。Eu~(3+)结合水共振峰的化学位移、络合物的化学交换饱和转移特性和结合水驻留寿命(τ_m)随侧臂化学结构的不同而发生显著变化。酮氧给体原子取代了酰胺氧给体原子，延长了水的停留寿命(τm)，降低了Eu~(3+)结合水分子的化学位移(Δω)。这些实验结果和密度泛函理论(DFT)的计算结果表明，在这些配合物中引入弱给电子氧原子会导致配位场变得更弱，Eu3+离子上带更多正电荷，水驻留寿命延长，正如解离机理所预期的那样。这些结果为顺磁性CEST试剂的设计提供了新的见解，使其具有更慢的水交换动力学，使其更有效地用于活体成像应用。
A series of new 1,4,7,10-tetraazacyclododecane-derivatives having a combination of amide and ketone donor groups as side-arms were prepared and their complexes with europium(III) studied in detail by high resolution NMR spectroscopy. The chemical shift of the Eu3+-bound water resonance, the chemical exchange saturation transfer (CEST) characteristics of the complexes, and the bound water residence lifetimes (τm) were found to vary dramatically with the chemical structure of the side-arms. Substitution of ketone oxygen donor atoms for amide oxygen donor atoms resulted in an increase in residence water lifetimes (τm) and a decrease in chemical shift of the Eu3+-bound water molecule (Δω). These experimental results along with density functional theory (DFT) calculations demonstrate that introduction of weakly donating oxygen atoms in these complexes results in a much weaker ligand field, more positive charge on the Eu3+ ion and an increased water residence lifetime as expected for a dissociative mechanism. These results provide new insights into the design of paramagnetic CEST agents with even slower water exchange kinetics that will make them more efficient for in vivo imaging applications.
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影响因子：
1.8
作者：
Zhang, SR;Jiang, XY;Sherry, AD
通讯作者：
Sherry, AD
影响因子：
2.1
作者：
Zhang, Y;Wu, LB;Li, BG
通讯作者：
Li, BG
影响因子：
4.4
作者：
DICKSON, RM;BECKE, AD
通讯作者：
BECKE, AD
影响因子：
2.2
作者：
Ward, KM;Aletras, AH;Balaban, RS
通讯作者：
Balaban, RS
影响因子：
4.6
作者：
Krogh-Jespersen, Karsten;Romanelli, Michael D.;Brennan, John G.
通讯作者：
Brennan, John G.