Monte Blau

RADIOIODINE-LABELED AMINES AS BRAIN IMAGING AGENTS

Abstract A series of 125I-labeled 2-hydroxy-5-iodo-benzamides and -benzylamines were synthesized and evaluated as brain imaging agents. The compounds were labeled by a rapid aqueous exchange reaction. This procedure is suitable for kit preparation. Partition coefficients at pH 7.0 and 7,4, protein binding, and biodistribution in rats were studied. Initial brain uptake (2 m after i.v. injection) of the benzylamines was as high as 3,2% of the injected dose, but the benzamides exhibited much lower uptake (~1%). Two compounds N, N-dimethyl-N′-ethyl-N′(2-hydroxy-5-iodo-benzyl)-1,2-ethanediamine and N,N-dimethyl-N′-(2-hydroxy-5-iodobenzyl)-1,3-propanediamine, have biodistributions which indicate potential usefulness as 123I-labeled brain imaging agents.