Santonin (STN)

Santonin is a drug which was widely used in the past as an anthelminthic, a drug that expels parasitic worms (helminths) from the body, by either killing or stunning them. Santonin can be converted to santonic acid (C15H20O4) via based-catalyzed hydrolysis followed by a multistep rearrangement process. Santonin dissolves in alkalies with formation of salts of this carboxylic acid. Santonin, in acetic acid solution, when exposed to sunlight for about a month, is converted into (colorless) photosantonic acid (C15H22O5) which is generally regarded as less toxic. The ethyl ester of the latter is obtained when an alcoholic solution of santonin is exposed to sunlight (Sestini). Santonin is an organic chemical consisting of colorless flat prisms, turning slightly yellow from the action of light and soluble in alcohol, chloroform and boiling water.