Template:Infobox compound Thioterpineol, commonly known as grapefruit mercaptan is an organic compound that occurs naturally in grapfruits. The compound is a terpineol in which a hydroxy group has been replaced by a thiol, hence the name of the compound. Thioterpineol is the primary chemical responsible for the strong aroma of grapfruit. The decomposition products of thioterpineol usually have a highly disagreeable odor.