Synthesis and characterization of [125I]N-(2-aminoethyl)-4-iodobenzamide as a selective monoamine oxidase B inhibitor.
We described the radiosynthesis of an analog of Ro 16-6491, [125I]N-(2-aminoethyl)-4-iodobenzamide, for SPECT exploration of the monoamine oxidase B (MAO-B) in human brain. The radiolabelling was carried out by nucleophilic exchange of the brominated precursor at solid-state phase in presence of ammonium sulphate. The radiochemical purity of radioiodinated product was higher than 95%. In comparison with Ro 16-6491, the in vitro studies showed a good selectivity of stable N-(2-aminoethyl)-4-iodobenzamide for MAO-B but a slightly lower affinity. Biodistribution studies in the rat showed a high and selective uptake of this compound in the pineal gland 1 h after i.v. injection. The cerebral uptake was low, but the coupling of [125I]N-(2-aminoethyl)-4-iodobenzamide with a lipophilic radical to enhance the passage through the blood-brain barrier can be envisaged.
Rafii
H
H
INSERM U316, Laboratoire de Biophysique Médicale et Pharmaceutique, UFR des Sciences Pharmaceutiques, Tours, France.
Chalon
S
S
Ombetta
J E
JE
Frangin
Y
Y
Garreau
L
L
Dognon
A M
AM
Lena
I
I
Bodard
S
S
Vilar
M P
MP
Besnard
J C
JC
D000818:Animals; D001549:Benzamides / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D001549:Benzamides; D007457:Iodine Radioisotopes; D008996:Monoamine Oxidase Inhibitors; C051040:Ro 16-6491; D008995:Monoamine Oxidase