Underlining the Importance of Peripheral Protic Functional Groups to Enhance the Proton Exchange of Gd-Based MRI Contrast Agents.

ABSTRACT: In this study, we report the synthesis and the equilibrium, kinetic, relaxation, and structural properties of two new Gd^III complexes based on modified 10-(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (HPDO3A) designed to modulate the relaxivity at acidic and basic pH due to intra- and intermolecular proton exchange. The presence of a carboxylic or ester moieties in place of the methyl group of HPDO3A allowed differentiation of a protic and nonprotic functional group, highlighting the importance of the formation of an intramolecular hydrogen bond between the coordinated hydroxyl and the carboxylate groups for proton exchange (k_H = 1.5 × 10¹¹ M^-1 s^-1, k_OH = 1.7 × 10⁹ M^-1</

SUBMITTER: Boccalon M 

PROVIDER: S-EPMC8769378 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature