Iron(II) PARACEST MRI Contrast Agents
Citations Over TimeTop 10% of 2011 papers
Abstract
The first examples of Fe(II) PARACEST magnetic resonance contrast agents are reported (PARACEST = paramagnetic chemical exchange saturation transfer). The iron(II) complexes contain a macrocyclic ligand, either 1,4,7-tris(carbamoylmethyl)-1,4,7-triazacyclononane (L1) or 1,4,7-tris[(5-amino-6-methyl-2-pyridyl)methyl]-1,4,7-triazacyclononane (L2). The macrocycles bind Fe(II) in aqueous solution with formation constants of log K = 13.5 and 19.2, respectively, and maintain the Fe(II) state in the presence of air. These complexes each contain six exchangeable protons for CEST which are amide protons in [Fe(L1)](2+) or amino protons in [Fe(L2)](2+). The CEST peak for the [Fe(L1)](2+) amide protons is at 69 ppm downfield of the bulk water resonance whereas the CEST peak for the [Fe(L2)](2+) amine protons is at 6 ppm downfield of bulk water. CEST imaging using a MRI scanner shows that the CEST effect can be observed in solutions containing low millimolar concentrations of complex at neutral pH, 100 mM NaCl, 20 mM buffer at 25 °C or 37 °C.
Related Papers
- A GEOMETRIC MEAN IN THE FURUTA INEQUALITY(2002)
- Susquehanna Chorale Spring Concert "Roots and Wings"(2017)
- Коммуникaтивно- прaгмaтический aнaлиз дипломaтических бумaг (нa основе вербaльных нот)(2018)
- → ФОРМИРОВAНИЕ ГОТОВНОСТИ БУДУЩИХ ПЕДAГОГОВ К ОРГAНИЗAЦИИ РAБОТЫ ПО РAЗВИТИЮ ВAЛЕОЛОГИЧЕСКОЙ КУЛЬТУРЫ ШКОЛЬНИКОВ(2023)