Terpenes: Pinene

Pinene is a bicyclic monoterpene made up of α-pinene and beta-pinene; both of which are a separate pinene terpene found in pine resin and the resins of other conifers.

Molecular Weight: 136.238 g/mol

Density:

Melting Point: −64 °C (−83 °F; 209 K)

Boiling Point: 155 °C (311 °F; 428 K)

While on a hike along the Mogollon Rim a week or so ago I stopped to read one of those signs that told us about something along the trail, this particular sign was about Pine trees. It said that Native Americans in the area used the pine needle from these same trees for everything from hair care to a decoction that treated a bad cough. Ancient Chinese medicine also uses the pinene terpene for reducing inflammation, and as an expectorant much like the Native Americans. Along with pine and other conifers, α-Pinene can be found in camphorweed and big sagebrush among other common plants. The aroma of α-pinene is much like turpentine as it is a main constituent in the substance, if we’re smelling for pine trees we’ll often find the buds with Pinene. Pinene is often used in the chemical and perfume industries for products like artificial deodorants. The terpenoid is said to help us maintain focus, work as an expectorant, and fight inflammation.

This reactive hydrocarbon is prone to skeletal rearrangements, so when attempting to perform hydrogen halide addition with alkene functionality we will often end up with a rearranged product. According to PubChem, with concentrated sulfuric acid and ethanol we are often left with terpineol and ethyl ether. Glacial acetic acid give the corresponding acetate ester while dilute acids we mostly get terpin hydrate. Most times a pinene terpene is acquired by using a distillate on turpentine but it has also been isolated using cedar wood oil. Jack Herer, Dutch Treat, Romulan, OG Kush, and Blue Dream are a few cannabis strains that test high for this terpenoid.