460986-10-1Relevant articles and documents
2-HYDROXY-1-OXO 1,2 DIHYDRO ISOQUINOLINE CHELATING AGENTS
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Page/Page column 110; 111, (2010/11/28)
The invention provides a new class of strongly chelating multidentate ligands based on a 2-hydroxy-1-oxo-1,2-dihydro-isoquinoline-3-carboxylic acid scaffold (hereafter 1,2-HOIQO) in combination with polyamine backbones. The extremely stable bidentate 1,2- HOIQO moiety can be synthesized by standard synthetic methodology on a large scale. An advantageous feature is the possibility to introduce a wide range of substituents on the benzene ring by standard transformations (like electrophilic aromatic substitutions). This allows, for example, for the tuning of chemical, photophysical, and solubility properties, as well as the attachment of functional moieties, relevant for sensing and imaging applications (e.g. DNA, proteins, antibodies, fluorophores, etc.). The combination of the 1,2-HOIQO chelators with polyamine backbones provides very strongly binding ligands for a variety of metals including first-row transition metals, lanthanides, actinides, etc. Metal complexes of this kind are expected to be useful in a number of applications (e.g. luminescence, MRI, actinide sequestering, metal chelation therapy, metal radioisotope labeling, etc.).
Synthesis and initial evaluation for in vivo chelation of Pu(IV) of a mixed octadentate spermine-based ligand containing 4-carbamoyl-3-hydroxy-1-methyl-2(1H)-pyridinone and 6-carbamoyl-1-hydroxy-2(1H)-pyridinone
Xu, Jide,Durbin, Patricia W.,Kullgren, Birgitta,Ebbe, Shirley N.,Uhlir, Linda C.,Raymond, Kenneth N.
, p. 3963 - 3971 (2007/10/03)
An improved synthesis for a series of 1-hydroxy-2(1H)-pyridinone-based octadentate ligands is reported. The mixed chelate, octadentate ligand, 3,4,3-LI(1,2-Me-3,2-HOPO), was designed, synthesized, and tested for in vivo chelation of Pu in a mouse model. This ligand incorporates both 1,2-HOPO and Me-3,2-HOPO metal chelating units; the latter has higher affinity toward actinide ions than does 1,2-HOPO at physiological pH. Injected or administered orally to fasted or normally fed mice at the standard clinical dose 30 μmol/kg, both 3,4,3-LI(1,2-HOPO) and 3,4,3-LI(1,2-Me-3,2-HOPO) remove significantly more Pu than injected CaNa3DTPA. Injected doses of 0.1 μmol/kg of these HOPO ligands are as effective as 30 μmol/kg of injected CaNa3-DTPA. Ten daily injections of 30 μmol/kg of a HOPO ligand did not induce detectable acute toxicity in mice. The mixed HOPO ligand is somewhat more effective than 3,4,3-LI(1,2-HOPO) when given orally, and the enhanced reduction of liver Pu by the mixed ligand is statistically significant. Thus, both octadentate HOPO ligands meet the criterion of low toxicity at doses that are more effective than the standard dose of CaNa3DTPA. Their improved effectiveness at low dose along with great oral activity (despite low gastrointestinal absorption) implies that new treatment regimens can be developed using the HOPO ligands alone or as adjuncts to CaNa3DTPA therapy, which will greatly exceed the amount of Pu excretion that is achievable with CaNa3DTPA alone.
