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Synthesis of bifunctional dota derivatives
METALS IN MEDICINE
163
A030
POLYMERIC CONTRAST AGENTS FOR MAGNETIC RESONANCE IMAGING. F. Armitage and Q. E. Ria, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA. Preparations and properties of polymeric gadolinium contrast agents for magnetic resonance imaging are described. The agents are based on Gd(II1) chelates linked by esterification to various polysaccharides of different average molecular weights and structures. High loading of the polymer with chelate was achieved Imaging studies indicate t?t the (-1 Gd/2 monosaccharides). polymeric agents are distinctly different from [GdDTPA] - in biodistribution and may have superior properties for certain MRI applications.
A031
LANTHANIDE CHELATESAS MRI ENHANCEMENT AGENTS. F. E. Hahn and J. Mohr, lnstltut fur Anorganische und Analytische Chemie Technische Unlversltat Berlin, D-l 880 Berlin 12, W-Germany
Lanthanide trlflates (Ln(CF3S03)3, Ln=Pr, Yb, Lu) react in THF with trlethanolamine to give the complex cations (Ln[N(C2H8OH)3]2.THF} 3 +. The crystal structure analysis of the Pr and Yb derlvatlve show nine coordinated lanthanide ions (two triethandamlne-N, six triethanolamine-0, one THF-0). The distance between OHgroups of differenttriethanolamine ligands fall in the range of 2.81-2.88 A for Ln =Yb and 2.92 - 3.11 A for Ln= Pr, respectively.These distances can be bridged wlth R2Si groups to give the very stable bicyclic complexes. Strategies for the introduction of the bridging groups will be discussed.
SYNTHESIS OF BIFUNCTIONAL DOTA DERIVATIVES Thomas J. McMurry and Otto A. Gansow, National Cancer Institute Radiation Oncology Branch Building ID, Room B3B69, Bethesda, MD 20892 The radionuclides 203Pb (279 KeV,tI/2 52.1 h) and 2I2Pb (tI/2 19.6 hr) are candidates for use with monoclonal antibody in nuclear medicine. While 203Pb is ideal for single photon emission tomooraohy (SPECT), 2I2Pb could serve as the source of its cytotoxic alpha emitting daughter in therapeutic applications. We have recently shown that Pb(II)DOTA is inert over the pH range 4-12, suggesting the utility of a bifunctional DOTA chelate. We report here a general s.ynthesis of bifunctional DOTA molecules, where the key step is a high dilution cyclization to form a macrocyclic diamide precursor.
A032
163
A030
POLYMERIC CONTRAST AGENTS FOR MAGNETIC RESONANCE IMAGING. F. Armitage and Q. E. Ria, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA. Preparations and properties of polymeric gadolinium contrast agents for magnetic resonance imaging are described. The agents are based on Gd(II1) chelates linked by esterification to various polysaccharides of different average molecular weights and structures. High loading of the polymer with chelate was achieved Imaging studies indicate t?t the (-1 Gd/2 monosaccharides). polymeric agents are distinctly different from [GdDTPA] - in biodistribution and may have superior properties for certain MRI applications.
A031
LANTHANIDE CHELATESAS MRI ENHANCEMENT AGENTS. F. E. Hahn and J. Mohr, lnstltut fur Anorganische und Analytische Chemie Technische Unlversltat Berlin, D-l 880 Berlin 12, W-Germany
Lanthanide trlflates (Ln(CF3S03)3, Ln=Pr, Yb, Lu) react in THF with trlethanolamine to give the complex cations (Ln[N(C2H8OH)3]2.THF} 3 +. The crystal structure analysis of the Pr and Yb derlvatlve show nine coordinated lanthanide ions (two triethandamlne-N, six triethanolamine-0, one THF-0). The distance between OHgroups of differenttriethanolamine ligands fall in the range of 2.81-2.88 A for Ln =Yb and 2.92 - 3.11 A for Ln= Pr, respectively.These distances can be bridged wlth R2Si groups to give the very stable bicyclic complexes. Strategies for the introduction of the bridging groups will be discussed.
SYNTHESIS OF BIFUNCTIONAL DOTA DERIVATIVES Thomas J. McMurry and Otto A. Gansow, National Cancer Institute Radiation Oncology Branch Building ID, Room B3B69, Bethesda, MD 20892 The radionuclides 203Pb (279 KeV,tI/2 52.1 h) and 2I2Pb (tI/2 19.6 hr) are candidates for use with monoclonal antibody in nuclear medicine. While 203Pb is ideal for single photon emission tomooraohy (SPECT), 2I2Pb could serve as the source of its cytotoxic alpha emitting daughter in therapeutic applications. We have recently shown that Pb(II)DOTA is inert over the pH range 4-12, suggesting the utility of a bifunctional DOTA chelate. We report here a general s.ynthesis of bifunctional DOTA molecules, where the key step is a high dilution cyclization to form a macrocyclic diamide precursor.
A032