Biologically Active Aliphatic Acetogenins from Specialized Idioblast Oil Cells

More than three decades ago, Kashman and coworkers [1,2] reported for the first time a class of closely related compounds from avocados (Lauraceae). This class of compounds contains several highly oxygenated long-chain acetylenic and olefinic natural products derived from fatty acids (e.g. possibly C- 18 oleic, linoleic, linolenic, or stearic acid as precursors). These products form part of a group of compounds known as the “biologically active aliphatic acetogenins”, the distribution of which is thought to be restricted to the Annonaceae and Lauraceae. Current studies indicate that the Lauraceous acetogenins are synthesized during early plant development from specialized idioblast oil cells and transported from the oil cells to other parts of the plant. While idioblast oil cells are found throughout the plant kingdom, their function in many plant families has been the focus of considerable speculation because little is known about the chemistry or biological activity of the oil in the cells. Until recently, the idioblast cells were generally viewed simply as unusual storage organs. In avocados, increasing evidence indicates that the cells, and the oil they contain, may play an important defensive role against pathogens and insects. Several of the compounds produced in avocado oil cells, reported to occur almost exclusively in the genus Persea, are now known to have antibacterial, antifungal, and insecticidal activity. In the present paper we review the distribution, synthesis, biological activity, and mode of action of the most studied Lauraceous acetogenins: the diene persin, (12Z, 5Z)-1-acetoxy-2-hydroxy-4-oxo-heneicosa-12,15-diene, and the persin-derived furans known as avocadofurans.