Synthesis of 3-amino-2-(3-indolyl)propanol and propanoate derivatives and preliminary cardiovascular evaluation in rats.

A series of tryptamine analogues has been prepared and tested for their 5-HT1 receptor agonist properties. The incorporation of an alkoxy group at the C-5 position of the indole nucleus resulted in a short-lived and dose-dependent immediate antihypertensive and bradycardic response in anaesthetized spontaneously hypertensive rats (SHR). In addition, a carbomethoxy function at the beta-position of the side-chain of the tryptamines significantly increased the mean resting arterial blood pressure (MAP) in pithed rats and also produced contraction of the canine basilar artery in a dose-dependent fashion. Structure-activity relationships (SAR) suggest that the 5-alkoxy group is an important pharmacophore in the production of the antihypertensive effect and that the introduction of a hydroxymethylene group on the side-chain, instead of the carbomethoxy group, changed the receptor affinity profile.