Characterization of Novel Gd-DOTA Related Contrast Agents for Magnetic Resonance Imaging (MRI)

This work focuses on the characterization of a new potential contrast agent con- sisting of β-cyclodextrin and 1,4,7,10-tetraazacyylododecan-4,7,10-triocta-1-methyl[(4- aminophenyl)methyl]phosphinoic acid, short for DO3APABn . Using 2D NMR experi- ments, the hydrogen and carbon spectrum signals of both molecules were assigned. There was a temperature dependency studied in DO3APABn . By evaluating 13 C relaxation, re- laxation times T1, T2 and Nuclear Overhauser effect were determined. Using the isotropic reorientation model, the rotational correlation time was numerically calculated from the measured values of T1. From the rotational correlation time, the most rigid part of the molecule was found to be the cycle (τc = 264-308 ps). The most mobile is the aromatic methyl phosphine arm, whose correlation time is about half that of the cycle (139-156 ps).