phorbol

Phorbol is a natural, plant-derived organic compound. It is a member of the tigliane family of diterpenes. Phorbol was first isolated in 1934 via the hydrolysis of croton oil, which is derived from the seeds of the purging croton, Croton tiglium. The structure of phorbol was determined in 1967. Various esters of phorbol have important biological properties, the most notable of which is the capacity to act as tumor promoters through activation of protein kinase C. They mimic diacylglycerols, glycerol derivatives in which two hydroxyl groups have reacted with fatty acids to form esters. The most common and potent phorbol ester is 12-O-tetradecanoylphorbol-13-acetate (TPA), also called phorbol-12-myristate-13-acetate (PMA), which is used as a biomedical research tool in contexts such as models of carcinogenesis.

==History and source== Phorbol is a natural product found in many plants, especially those of the Euphorbiaceae and Thymelaeaceae families. Phorbol and phorbol esters are the active constituents of the highly toxic New World tropical manchineel tree (Hippomane mancinella). It is very soluble in most polar organic solvents, as well as in water. In the manchineel, this leads to an additional exposure risk during rain, where liquid splashing from an undamaged tree may also be injurious. Contact with the tree or consumption of its fruit can lead to symptoms such as severe pain and swelling.