Occurs naturally in plants with hallucinogenic properties. Isoln from the leaves of Prestonia amazonica (Benth.) Macbride (Haemadictyon amazonicum Spruce & Benth.), Apocynaceae: Hockstein, Paradies, J. Am. Chem. Soc. 79, 5735 (1957). Metabolism: St. Szára, Experientia 12, 441 (1956); B. R. Sitaram et al., Biochem. Pharmacol. 36, 1509 (1987). Relationship between hallucinogenic activity and electronic configuration: Snyder, Merril, Proc. Natl. Acad. Sci. USA 54, 258 (1965). Synthesis: I. Fleming, M. Woolias, J. Chem. Soc. Perkin Trans. 1 1979, 829. Differential interaction with serotonin receptor subtypes: A. V. Deliganis et al., Biochem. Pharmacol. 41, 1739 (1991). Fluorometric detection: O. Jules et al., Anal. Chim. Acta 169, 355 (1985). Review of biosynthesis, metabolism and bioactivity: S. A. Barker et al., Int. Rev. Neurobiol. 22, 83-110 (1981).