Functions and Structure of Plant Terpenes
Functions and structure of plant terpenes
Terpenes are an enormous class of organic compounds, that are produced by a wide variety of plants and fungi, especially conifers. Terpenes are also produced by some of the living organisms, like swallowtail butterflies. They emit terpenes from their osmeterium. Terpenes are important materials for a plant as components of its body and as a material to protect it from external enemies since it has a strong smell and colorless. Terpenes are found in biological pigments, such as chlorophyll and retinal, and steroids play important roles in membranes and as the basis for a class of hormones involved in chemical signaling. There are many use of terpenes. In our daily life,terpenes are used in flavor and fragrances,additives to rubber and plastics,paints and construction materials. Many terpenes are hydrocarbons, but oxygen-containing compounds such as alcohols, aldehydes or ketones are also found. Their building block is the hydrocarbon isoprene, CH2=C(CH3)-CH=CH2, Terpene hydrocarbons therefore have molecular formulas (C5H8)n. The larger structures are made up of several isoprene units, usually by "head-to-tail" linked isoprene units. However, isoprene it self does not carry out the process of building up the large structure, but activated process. IPP ( isopentenyl pyrophosphate) and DMAPP( dimethylallyl pyrophosphate) are the two components of the biosynthesis pathway of terpene. IPP is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, totally unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP(2-Methyl-D-erythritol-4-phosphate)-pathway, which is initiated from C5-sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. The hemiterpene isoprene, which contains five carbons,an isoprene unit, is a gas emitted into
Terpenes are an enormous class of organic compounds, that are produced by a wide variety of plants and fungi, especially conifers. Terpenes are also produced by some of the living organisms, like swallowtail butterflies. They emit terpenes from their osmeterium. Terpenes are important materials for a plant as components of its body and as a material to protect it from external enemies since it has a strong smell and colorless. Terpenes are found in biological pigments, such as chlorophyll and retinal, and steroids play important roles in membranes and as the basis for a class of hormones involved in chemical signaling. There are many use of terpenes. In our daily life,terpenes are used in flavor and fragrances,additives to rubber and plastics,paints and construction materials. Many terpenes are hydrocarbons, but oxygen-containing compounds such as alcohols, aldehydes or ketones are also found. Their building block is the hydrocarbon isoprene, CH2=C(CH3)-CH=CH2, Terpene hydrocarbons therefore have molecular formulas (C5H8)n. The larger structures are made up of several isoprene units, usually by "head-to-tail" linked isoprene units. However, isoprene it self does not carry out the process of building up the large structure, but activated process. IPP ( isopentenyl pyrophosphate) and DMAPP( dimethylallyl pyrophosphate) are the two components of the biosynthesis pathway of terpene. IPP is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, totally unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP(2-Methyl-D-erythritol-4-phosphate)-pathway, which is initiated from C5-sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. The hemiterpene isoprene, which contains five carbons,an isoprene unit, is a gas emitted into
References: Books Cane, David E., ed. Comprehensive Natural Products Chemistry, Vol. 2: Isoprenoids Including Carotenoids and Steroids. Oxford: Elsevier, 1999. Croteau, Rodney B. "The Discovery of Terpenes." In Discoveries in Plant Biology, Vol. I, eds. Shain-Dow Kung and Shang-Fa Yang. Singapore: World Scientific, 1998. Langenheim, Jean H. "Higher Plant Terpenoids: A Phytocentric Overview of Their Ecological Roles." Journal of Chemical Ecology 20 (1994): 1223-80. Glencoe, Peter Raven, Peter H Raven. "Lipids: Hydrophobic Molecules" In Biology. McGraw-Hill, 2010 Links http://vcampus.uom.ac.mu/upload/public/2003122103128.pdf http://www.chemie.fu-berlin.de/chemistry/oc/terpene/terpene_en.html http://vohweb.chem.ucla.edu/voh/classes%5Cspring09%5C30CID12%5CTerpenes.pdf