Abstract
Abstract— Various 5‐HT and tryptamine analogues have been examined as inhibitors of [3H]5‐HT uptake into rat hypothalamic homogenates. Acetylation of the terminal amino group or methylation of the hydroxyl group of 5‐HT resulted in compounds having a reduced affinity for the serotonin uptake site. This also occurred when the hydroxyl group of 5‐HT was substituted in other positions on the benzene ring. Substitution of the tryptamine side chain in the a‐position by methyl or ethyl groups, but not by a carboxyl function, enhanced the affinity for the 5‐HT uptake site. Increasing the tryptamine side chain by one carbon atom also resulted in a more potent compound. Several of the compounds tested are known to be either hallucinogens or antidepressants.