Psychoactive alkaloid found in the leaves of the khat plant, Catha edulis Forsk., Celastraceae. Prepn of racemic compd: L. Behr-Bergowski, Ber. 30, 1515 (1897); S. Gabriel, ibid. 41, 1127 (1908). Isoln from C. edulis: X. Schorno, E. Streinegger, Experientia 35, 572 (1979); and identification as active constituent of khat: D. W. Peterson et al., Life Sci. 27, 2143 (1980). Stereospecific synthesis from norephedrine: B. D. Berrang et al., J. Org. Chem. 47, 2643 (1982). Metabolism in humans: R. Brenneisen et al., J. Pharm. Pharmacol. 38, 298 (1986). HPLC determn in urine: K. Mathys, R. Brenneisen, J. Chromatogr. 593, 79 (1992). Quantitative determn in khat: A. M. Al-Obaid et al., J. Pharm. Biomed. Anal. 17, 321 (1998). Review of pharmacology: P. Kalix, Pharmacol. Toxicol. 70, 77-86 (1992).