Hydroxamamide as a chelating moiety for the preparation of 99Tcm radiopharmaceuticals (I).
Hydroxamamides contain a nitrogen and an oxygen as donor atoms, and can be synthesized by the simple reaction of nitriles with hydroxylamine. Benzohydroxamamide (BHam) was investigated as a new ligand for 99Tcm. The yield of the 99Tcm-BHam complex was determined by thin-layer chromatography using cellulose strips. A high yield of the complex was obtained at room temperature over a wide pH range, even at BHam concentrations as low as 5 x 10(-7) M. Cellulose acetate electrophoresis indicated that the complex was uncharged. When the 99Tcm-BHam complex was injected into mice, it was cleared gradually from the blood by means of the hepatobiliary system with low urinary excretion. Uptake by the stomach and the spleen was low. These results demonstrate the high affinity of BHam for 99Tcm and the high stability of the 99Tcm-BHam complex. The hydroxamamide group may be a promising chelating moiety for designing new 99Tcm radiopharmaceuticals.
Nakayama
M
M
Faculty of Pharmaceutical Sciences, Kumamoto University, Japan.
Saigo
H
H
Kai
E
E
Koda
A
A
Ozeki
H
H
Harada
K
K
Sugii
A
A
Tomiguchi
S
S
Kojima
A
A
Hara
M
M
D000818:Animals; D002614:Chelating Agents; D006877:Hydroxamic Acids / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D008024:Ligands; D008297:Male; D051379:Mice; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D014018:Tissue Distribution
D002614:Chelating Agents; D006877:Hydroxamic Acids; D008024:Ligands; D015609:Organotechnetium Compounds; C077176:technetium Tc 99m benzohydroxamamide complex