title: Synthesis, characterization and biodistribution of tris(beta-diketonato)technetium(III) complexes.
abstract: New tris(beta-diketonato) complexes of trivalent 99Tc/99mTc with the ligands hexane-2,4-dione, heptane-2,4-dione, heptane-3,5-dione, and octane-3,5-dione were synthesized by reduction of pertechnetate with dithionite in the presence of excess beta-diketone. The complexes were purified by HPLC, identified by elemental analysis and FAB mass spectrometry, and characterized by vis./u.v./i.r. spectrophotometry. The hexane-2,4-dionato complex crystallizes in the monoclinic space group P21/c, isostructurally with pentane-2,4-dionatotechnetium(III). Biodistribution measurements in mice showed the neutral and lipophilic 99mTc-diketonato complexes to penetrate the blood-brain barrier. However, increasing lipophilicity decreased the brain uptake except for the heptane-2,4-dionato complex, which displayed the highest uptake of 0.82% injected dose/g.
authors.affiliation: Institut für Chemie 1 (Nuklearchemie), Forschungszentrum (KFA) Jülich GmbH, Fed. Rep. Germany.
authors.forename: K
authors.initials: K
authors.lastname: Leesmeister
authors.forename: K
authors.initials: K
authors.lastname: Schwochau
mesh_terms: D000818:Animals; D007659:Ketones / Q000138:chemical synthesis*; D008024:Ligands; D013058:Mass Spectrometry; D051379:Mice; D000442:Octanols; D015609:Organotechnetium Compounds / Q000138:chemical synthesis*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism; D012995:Solubility; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013667:Technetium; D014018:Tissue Distribution; D014867:Water; D014961:X-Ray Diffraction
chemical_list: D007659:Ketones; D008024:Ligands; D000442:Octanols; D015609:Organotechnetium Compounds; D014867:Water; D012710:Serum Albumin, Bovine; D013667:Technetium