Has been found in starfish and sea urchins: A. Kossel, S. Edlbacher, Z. Physiol. Chem. 94, 264 (1915); in rock lobsters: L. Novellie, H. M. Schwartz, Nature 173, 450 (1954). Formation from caffeine by dec with barium hydroxide: Paulmann, Arch. Pharm. 232, 601 (1894). Prepd on a large scale from formaldehyde, sodium cyanide, and methylamine: Eschweiler, Ann. 279, 39 (1894); Baumann, J. Biol. Chem. 21, 563 (1915); Caverly, US 2720540 (1955 to du Pont); Leake, Brakebill, US 3009954 (1961 to Allied Chem.). Synthesis: M. Ebata et al., Bull. Chem. Soc. Jpn. 39, 2535 (1966). Review of syntheses: T. Shirai, Synthetic Production and Utilization of Amino Acids, T. Kaneko et al., Eds. (Wiley, New York, 1974) pp 184-186.