Pinene

Pinene (C₁₀H₁₆) is a bicyclic monoterpene chemical compound. There are two structural isomers of pinene found in nature: α-pinene and β-pinene. As the name suggests, both forms are important constituents of pine resin; they are also found in the resins of many other conifers, as well as in non-coniferous plants such as big sagebrush (Artemisia tridentata). Both isomers are used by many insects in their chemical communication system. The two isomers of pinene constitute the major component of turpentine.

Isomers

Biosynthesis

α-Pinene and β-pinene are both produced from geranyl pyrophosphate, via cyclisation of linaloyl pyrophosphate followed by loss of a proton from the carbocation equivalent.

Plants

Alpha-pinene is the most widely encountered terpenoid in nature and is highly repellant to insects.

Alpha-pinene appears in conifers and numerous other plants. Pinene is a major component of the essential oils of Sideritis spp. (ironwort) and Salvia spp. (sage).Cannabis also contains alpha-pinene. Resin from Pistacia terebinthus (commonly known as terebinth or turpentine tree) is rich in pinene. Pine nuts produced by pine trees contain pinene.