Its properties are due to the presence of a glucoside known as Morindin, which is compounded from glucose and probably a trioxy-methyl-anthraquinone.
The enzymes which act upon glucosides are many; the best known are emul sin and myrosin, which split up respectively amygdalin, the special glucoside of certain plants of the Rosaceae; and sinfgrin, which has a wide distribution among those of the Cruciferae.
As a free alkaloid) in the plant, but that it exists in the form of a glucoside, and that by the process of chewing this glucoside is split up by one of the ferments in the saliva into the free alkaloid and sugar.
A valuable medicinal glucoside named salicin (q.v.) is also extracted from the bark.
It is found in the volatile oils of Spiraea, and can be obtained by the oxidation of the glucoside salicin, (C13H1807), which is found in willow bark.