Orthogonal synthesis of a heterodimeric ligand for the development of the Gd(III)-Ga(III) ditopic complex as a potential pH-sensitive MRI/PET probe

• Published in: Organic & biomolecular chemistry Vol. 11; no. 10; p. 1683
• Main Authors: Vologdin, Nikolay, Rolla, Gabriele A, Botta, Mauro, Tei, Lorenzo
• Format: Journal Article
• Language: English
• Published: England 13-02-2013
• Subjects: Contrast Media - chemical synthesis; Contrast Media - chemistry; Dimerization; Gadolinium - chemistry; Gallium - chemistry; Hydrogen-Ion Concentration; Ligands; Magnetic Resonance Imaging; Molecular Probes - chemical synthesis; Molecular Probes - chemistry; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Positron-Emission Tomography
• ISSN: 1477-0539
• DOI: 10.1039/c2ob27200h

A heterodimeric polyaminocarboxylate ligand based on a DO3A-sulfonamide linked to AAZTA (6-amino-6-methylperhydro-1,4-diazepinetetracarboxylic acid) was synthesised via an orthogonal pathway in order to differentiate the two chelating cages and allow the formation of a Gd(III)-Ga(III) heteroditopic complex. The goal is to create a smart MRI/PET probe with pH dependent relaxivity and with the bimodal imaging approach that enables direct quantification of the stimulus, in this case pH. A (1)H NMR relaxometric study of the Gd-Ga heteroditopic complex addressed the pH modulation of the relaxivity and thus its possible use as an MRI pH sensitive probe.