Sapogenin glycosides. A type of glycoside widely distributed in plants. Each saponin consists of a sapogenin which constitutes the aglucon moiety of the molecule, and a sugar. The sapogenin may be a steroid or a triterpene and the sugar moiety may be glucose, galactose, a pentose, or a methylpentose. Poisonous towards the lower forms of life and used for killing fish by the aborigines of South America. Review and bibliography: R. J. McIlroy, The Plant Glycosides (Edward Arnold & Co., London, 1951) Chapter IX; Y. Birk, I. Peri in Toxic Const. Plant Foodst., I. E. Liener, Ed. (Academic Press, New York, 2nd ed., 1980) pp 161-182.