Comparative effects of stereoisomers of psychotomimetic phenylisopropylamines.

Abstract Stereoisomers, R(−) and S(+), of five psychotomimetic phenyliso-propylamines contracted isolated strips of sheep umbilical arteries. The compounds exhibited the following order of potency: 2,5-dimethoxy-4-bromo-amphetamine (DOB) > 2,5-dimethoxy-4-ethyl-amphetamine DOET) > 2,5-dimethoxy-4-methyl-amphetamine (DOM) > 2,5-dimethoxy-amphetamine (2,5-DMA) > 4-methoxy-amphetamine (PMA). Stereoselectivity was observed in that the R(−) isomers were more active than the S(+) isomers except for PMA. Evidence was obtained for the action of these hallucinogens on 5-hydroxytryptamine receptors. There was a general correlation of smooth muscle stimulating activity with known hallucinogenic activity.