Cytisine (Ulexin, Sophorin), C11H14N2O, an alkaloid discovered in 1818 by J. B. Chevreul in the seeds of laburnum (Cytisus Laburnum) and isolated by A. Husemann and W. Marmé in 1865 (Zeit. f. Chemie, 1865, i. p. 161). It is also found in the seeds of furze (Ulex europaeus), Sophora tormentosa, and Euchresta horsfieldii. It is extracted from the seeds by an alcoholic solution of acetic acid, and forms large crystals which melt at 153° C., and are easily soluble in water, alcohol and chloroform. It is a secondary and tertiary di-acid base, and is strongly alkaline in its reaction. Hydrogen peroxide oxidizes it to oxycytisine, C11H14N2O2, chromic acid to an acid, C11H9NO3, and potassium permanganate to oxalic acid and ammonia. It acts as a violent poison.
See further, P. C. Plugge, Arch. der Pharm. (1891), 229, p. 48 et seq.; A. Partheil, Ber. (1890), 23, p. 3201, Arch. der Pharm. (1892), 230, p. 448; M. Freund and A. Friedmann, Ber. (1901), 34, p. 615; and J, Herzig and H. Meyer, Monats. f. Chem. (1897), 18, p. 379.