Khare_1999_Nucl.Med.Biol_26_609

Four isomeric N-(halophenyl)trozamicol analogues (6a-d) were synthesized and evaluated as potential vesicular acetylcholine transporter (VAChT) ligands. Of the four compounds, N-(3-bromophenyl) trozamicol (6b) and N-(3-iodophenyl)trozamicol (6d) displayed the highest affinity for the VAChT in vitro, whereas the para-substituted compound 6c showed the lowest affinity for this transporter. Tissue distribution studies of N-(3-[125I]iodophenyl)trozamicol ([125I]6d, [125I)IPHT) suggest that the central distribution of the latter is consistent with cholinergic innervation. However, only moderate target-to-background ratios were obtained, suggesting little improvement over the N-(halobenzyl)trozamicols described previously.