Terpenes are a class of hydrocarbons, produced by many plants, particularly conifers. They are major components of resin, and of turpentine produced from resin.
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.
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.
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.
Important terpenes include:
- delta-3 carene
See also: Terpenoid