Relaxivity studies and X-ray structure of Gd(III)-diethylenetriamine-N,N ',N ''-triacetic acid-N,N ''-bis(2-methoxyphenethylamide) as a potential contrast agent for magnetic resonance imaging

A new bis(amide) derivative of diethylenetriamine-N,N,N',N",N"-pentaacetic acid (H(5)dtpa), diethylenetriamine-N,N',N"-triacelic-N,N"bis(2-methoxyphen ethylamide) (H3L), has been synthesized. The crystal structure of gadoliniu m(III) complex of H3L ([GdL]) has been determined by X-ray crystallography. The coordination sphere of Gd(III) comprises three amine nitrogens, two am ide oxygens, three carboxylic acid oxygens, and one water molecule. O-17 NM R shifts showed that the [DyL] complex had one inner-sphere water molecule. Relaxivity studies with the gadolinium(III) complex showed that they assoc iate strongly with proteins leading to a significant relaxivity enhancement . (C) 1999 Elsevier Science Ltd. All rights reserved.