A naturally occurring derivative of epinephrine, found together with metanephrine in urine and in certain tissues. Prepn: Fodor et al., Acta Chim. Acad. Sci. Hung. 1, 395 (1951), C.A. 49, 897 (1955); Axelrod et al., J. Biol. Chem. 233, 697 (1958); Heacock, Hutzinger, Chem. Ind. (London) 1961, 595.