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Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
¿Cómo influye el movimiento interno en la relajación de los protones de agua en complejos similares a Ln(III)DOTA?
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
Resumen
El movimiento interno en los complejos de lantánidos afecta la relajación de las moléculas de agua. Este estudio cuantifica este movimiento, revelando un ~ 10% de impacto en la relaxividad en los sistemas macromoleculares, crucial para los agentes de contraste de RM.
Área de la Ciencia:
- Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN) Espectroscopia de Resonancia Magnética Nuclear (RMN)
- Química de los Lantánidos
- Las dinámicas de relajación.
Sus antecedentes:
- La dinámica de las moléculas de agua es fundamental para comprender los procesos de relajación en los complejos de lantánidos.
- Los mecanismos de relajación de Curie y cuádrupolar juegan un papel importante en la relajación de protones y oxígeno / deuterio, respectivamente.
- El movimiento interno de las moléculas de agua unidas puede influir en la relaxividad general de los complejos lantánidos.
Objetivo del estudio:
- Para cuantificar el efecto del movimiento interno de la molécula de agua en los complejos de lantánidos.
- Para analizar los datos de RMN utilizando determinadas constantes de acoplamiento cuádrupolar.
- Evaluar el impacto de este movimiento en la relaxividad de protones de agua, particularmente en sistemas macromoleculares.
Principales métodos:
- Utilizando la contribución de Curie para la relajación de protones en complejos Tb(III).
- Empleando la relajación cuádrupolar de los núcleos 17O y 2H en complejos Eu (III).
- Determinación de la constante de acoplamiento cuadrupolar del oxígeno unido al agua.
- Analizando los datos de RMN 17O y 1H para el complejo [Gd(DOTA) ((H2O) ]- complejo.
Principales resultados:
- La constante de acoplamiento cuádrupolar para el oxígeno en el agua unida se determinó como chi ((Omicron) (((1 + eta ((Omicron) 2 / 3) 1/2 = 5.2 +/- 0.5 MHz.
- Se observaron diferentes tiempos de correlación rotacional para los vectores Gd (III) -O (agua) y Gd (III) -H (agua).
- La relación de la correlación rotacional multiplicada por tau (RH) /tau (RO) se calculó como 0,65 +/- 0,2.
Conclusiones:
- El movimiento interno de las moléculas de agua unidas puede afectar negativamente la relaxividad de los protones de agua.
- El efecto sobre la relaxividad se atenúa en los sistemas macromoleculares, estimado en alrededor del 10%.
- Comprender estas dinámicas es crucial para optimizar los agentes de contraste basados en lantánidos para aplicaciones como la RM.
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