内部运动如何影响Ln(III) DOTA类复合体中水质子的放松?
Frank A Dunand1, Alain Borel, André E Merbach
1Institut de Chimie Moléculaire et Biologique, Ecole Polytechnique Fédérale de Lausanne, EPFL-BCH, CH-1015 Lausanne, Switzerland.
Journal of the American Chemical Society
|January 24, 2002
概括
兰化物复合物的内部运动会影响水分子的放松. 这项研究量化了这种运动,揭示了大约10%的影响放松性在宏分子系统,对MRI对比剂至关重要.
科学领域:
- 核磁共振 (NMR) 光谱学 核磁共振 (NMR) 光谱学
- 兰化物化学 兰化物化学
- 放松动力学 放松动力学
背景情况:
- 水分子动力学对于理解兰化物复合物的放松过程至关重要.
- 基里和四极放松机制在质子和氧/放松中分别发挥着重要作用.
- 结合的水分子的内部运动可以影响兰化物复合物的整体放松性.
研究的目的:
- 量化水分子内部运动对兰坦化物复合体的影响.
- 使用确定的四极合常数分析NMR数据.
- 评估这种运动对水质子放松性的影响,特别是在宏分子系统中.
主要方法:
- 在Tb(III) 复合体中利用基里贡献来进行质子松.
- 采用Eu (III) 复合体中17O和2H核的四极放松.
- 确定结合的水氧的四极合常数.
- 分析17O和1HNMR数据,以检测[Gd(DOTA) ((H2O) ]-复合物.
主要成果:
- 结合水氧的四极合常数被确定为chi (?? 微米) 1+eta (?? 微米) 2/3) 1/2 = 5.2 +/- 0.5 MHz.
- 对于Gd (III) -O (水) 和Gd (III) -H (水) 矢量,观察到不同的旋转相关时间.
- 旋转相关性乘以tau (RH) /tau (RO) 的比率计算为0.65 +/- 0.2.2.
结论:
- 结合的水分子的内部运动可以对水质子的放松性产生负面影响.
- 对放松性的影响在宏分子系统中减弱,估计约为10%.
- 了解这些动态对于优化基于兰他尼德的对比剂对于MRI等应用至关重要.
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