title: Lanthanide(III) complexes of tris(amide) PCTA derivatives as potential bimodal magnetic resonance and optical imaging agents.
abstract: Lanthanide complexes of two tris(amide) derivatives of PCTA were synthesized and characterized. The relaxometric and luminescence properties of their lanthanide complexes were investigated as bimodal magnetic resonance (MR) and optical imaging agents. Luminescence studies show that one of the Tb(III) complexes dimerizes in solution at low millimolar concentrations, whereas the other may have a higher than expected coordination number in solution. The corresponding Gd(III) complexes display unusually high T(1) relaxivities and enhanced kinetic inertness compared to GdPCTA. These features suggest that these new chelates may be suitable for in vivo applications. The fast water-exchange rates observed for these complexes make them unsuitable as paramagnetic chemical exchange saturation transfer (PARACEST) agents.
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390, USA.
authors.forename: Federico A
authors.initials: FA
authors.lastname: Rojas-Quijano
authors.forename: Eniko Tircsóné
authors.initials: ET
authors.lastname: Benyó
authors.forename: Gyula
authors.initials: G
authors.lastname: Tircsó
authors.forename: Ferenc K
authors.initials: FK
authors.lastname: Kálmán
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Baranyai
authors.forename: Silvio
authors.initials: S
authors.lastname: Aime
authors.forename: A Dean
authors.initials: AD
authors.lastname: Sherry
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Kovács
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D003952:Diagnostic Imaging; D028581:Lanthanoid Series Elements; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D012996:Solutions; D014867:Water
chemical_list: C519843:3,6,9,15-tetraazabicyclo(9.3.1)pentadeca-1(15),11,13-triene-3,6,9-triacetic acid; D000085:Acetates; D000577:Amides; D019086:Bridged Bicyclo Compounds, Heterocyclic; D028581:Lanthanoid Series Elements; D008024:Ligands; D012996:Solutions; D014867:Water