Terpenes are a class of hydrocarbons, produced by many plants, particularly conifers. They are major components of resin, and of turpentine produced from resin. In chemistry, a hydrocarbon is a cleaning solution consisting only of carbon (C) and hydrogen (H). ... Divisions Green algae land plants (embryophytes) non-vascular embryophytes Hepatophyta - liverworts Anthocerophyta - hornworts Bryophyta - mosses vascular plants (tracheophytes) seedless vascular plants Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongue ferns seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering... Orders & Families Cordaitales † Pinales   Pinaceae - Pine family   Araucariaceae - Araucaria family   Podocarpaceae - Yellow-wood family   Sciadopityaceae - Umbrella-pine family   Cupressaceae - Cypress family   Cephalotaxaceae - Plum-yew family   Taxaceae - Yew family Vojnovskyales † Voltziales † The conifers, division Pinophyta, are one of 13 or 14 division level taxa within the Kingdom Plantae. ... Resin is a hydrocarbon secretion formed in special resin canals of many plants, from many of which (for example, coniferous trees) it is exuded in soft drops from wounds, hardening into solid masses in the air. ... Turpentine is a fluid obtained by distillation from resin obtained from trees, mainly various species of pine (Pinus). ...

Terpenes are derived from isoprene C₅H₈ and have the basic formula of multiples of it, i.e., (C₅H₈)_n. One can consider isoprene as one of nature's preferred building blocks. Isoprene Chemical name 2-Methyl-1,3-butadiene Chemical formula C5H8 Molecular mass 68. ...

The most commonly occurring terpenes are monoterpenes with the formula C₁₀H₁₆, of which numerous isomers exist. Others with formulae of C₁₅H₂₄ (sesquiterpenes), C₂₀H₃₂ (diterpenes), etc., also occur. In chemistry, isomers are molecules with the same chemical formula and often with the same kinds of bonds between atoms, but in which the atoms are arranged differently. ... The diterpenes are a class of molecules with 20 carbon atoms arranged as 4 isoprene units. ...

Their carbon skeletons are made up of isoprene units joined in a head-to-tail way. This is called the isoprene rule. These skeletons can be arranged in a linear way or forming rings.

The important plant photosynthetic pigment carotene is a tetraterpene, formula C₄₀H₆₄. Even most diverse matter as rubber, vitamin A₁ or cholesterol are essentially built up with isoprene building blocks. Leaf. ... In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... Carotene is a terpene, an orange photosynthetic pigment, important for photosynthesis. ... This article is about the material rubber, for other uses see Rubber (disambiguation) Rubber is an elastic hydrocarbon polymer which occurs as a milky emulsion (known as latex) in the sap of a number of plants but can also be produced synthetically. ... Retinol, the dietary form of vitamin A, is a fat-soluble, antioxidant vitamin important in vision and bone growth. ... Cholesterol is a steroid lipid, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. ...

Important terpenes include:

• alpha-Pinene
• beta-Pinene
• delta-3-Carene
• Limonene

See also: Terpenoid Limonene is a hydrocarbon, classed as a terpene. ... The terpenoids, sometimes referred to as isoprenoids, are a class of naturally occurring chemicals similar to terpenes, derived from five-carbon isoprene units assembled and modified in thousands of ways. ...

External links

• Institute of Chemistry - terpenes (http://www.chemie.fu-berlin.de/chemistry/oc/terpene/terpene_en.html)
• Structures of alpha pinene and beta pinene (http://www.chem.qmul.ac.uk/iubmb/enzyme/glossary/pinene.html)