Synthesis, characterization and relaxivity validations of Gd(III) complex of DOTA tetrahydrazide as MRI contrast agent

We report a novel Gadolinium(III) complex of (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetra(acetohydrazide) (Gd(III)L1) as a potential contrast agent for high resolution images in MRI and its molecular structure prediction by DFT calculations. The DOTA tetrahydrazide ligand framework (L1) was synthesized by the reaction of 1,4,7,10-tetraazacyclododecane (cyclen) with bromo derivative of conjugated t-butyl carbazate and followed by the subsequent cleavage of Boc moieties. The corresponding Gd(III) complex was prepared in an aqueous medium with the adjustment of pH to 7.0. The Gd(III)L1 complex shows the longitudinal relaxivity of 4.9 mM(-1)s(-1) and transverse relaxivity of 6.2 mM(-1) s(-1) at 37 degrees C. The as-prepared complex Gd(III)L1 displays the enhanced intensity of T1 weighted phantom MR images with various concentrations at 7.0 T MRI scanner, which pave the way to achieve higher resolution images in MRI. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a novel Gd(III) complex was reported as a potential contrast agent for high resolution MRI images, and its molecular structure was predicted through DFT calculations. The complex displayed high relaxivity and enhanced image intensity in MRI, paving the way for higher resolution imaging.