Dinuclear Fe(III) Hydroxypropyl-appended Macrocyclic Complexes as MRI Probes
| Autor: | Didar Asik, Joseph A. Spernyak, Samira M. Abozeid, Steven G. Turowski, Janet R. Morrow |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Macrocyclic Compounds
Potentiometric titration Serum albumin Contrast Media Serum Albumin Human 010402 general chemistry 01 natural sciences Medicinal chemistry Ferric Compounds Article Inorganic Chemistry chemistry.chemical_compound Mice Deprotonation Coordination Complexes Molecule Animals Humans Physical and Theoretical Chemistry Biphenyl Mice Inbred BALB C biology Molecular Structure 010405 organic chemistry Ligand Aryl Spin–lattice relaxation Magnetic Resonance Imaging 0104 chemical sciences chemistry biology.protein |
| Zdroj: | Inorg Chem |
| Popis: | Four high-spin Fe(III) macrocyclic complexes, including three dinuclear and one mononuclear complex, were prepared toward the development of more effective iron-based magnetic resonance imaging (MRI) contrast agents. All four complexes contain a 1,4,7-triazacyclononane macrocyclic backbone with two hydroxypropyl pendant groups, an ancillary aryl or biphenyl group, and a coordination site for a water ligand. The pH potentiometric titrations support one or two deprotonations of the complexes, most likely deprotonation of hydroxypropyl groups at near-neutral pH. Variable-temperature 17O NMR studies suggest that the inner-sphere water ligand is slow to exchange with bulk water on the NMR time scale. Water proton T1 relaxation times measured for solutions of the Fe(III) complexes at pH 7.2 showed that the dinuclear complexes have a 2- to 3-fold increase in r1 relaxivity in comparison to the mononuclear complex per molecule at field strengths ranging from 1.4 T to 9.4 T. The most effective agent, a dinuclear complex with macrocycles linked through para-substitution of an aryl group (Fe2(PARA)), has an r1 of 6.7 mM-1 s-1 at 37 °C and 4.7 T or 3.3 mM-1 s-1 per iron center in the presence of serum albumin and shows enhanced blood pool and kidney contrast in mice MRI studies. |
| Databáze: | OpenAIRE |
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