Cactus alkaloids. XLVII. N alpha-dimethylhistamine, a hypotensive component of Echinocereus triglochidiatus

Echinocereus triglochidiatus Engelm. var. neomexicanus (Standley) Standley ex W. T. Marshall is believed to cause psychotropic effects when consumed by the Mexican Tarahumara Indians. A phytochemical study was initiated with E. triglochidiatus Engelm. var. paucispinus Engelm. ex W. T. Marshall, which is more abundant in Texas. In the fractionated extracts three compounds, detected by thin-layer chromatography, were positive to Ehrlich's reagent, indicating the possible presence of indole alkaloids; however, a non-Erhlich positive alkaloid was crystallized as the dihydrochloride and subsequently identified (spectrometrically and via synthesis as N alpha, N alpha-dimethylhistamine dihydrochloride. The same compound was then detected chromatographically in the neomexicanus variety. This compound has peripheral hypotensive effects similar to histamine, and this action may help to explain the alleged psychotrophic effects of the cactus.