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:

• alpha-pinene
• beta-pinene
• delta-3 carene
• limonene

See also: Terpenoid

External links

• Institute of Chemistry - terpenes
• Structures of alpha pinene and beta pinene