Farnesene

Farnesene refers to several sesquiterpene hydrocarbons, most notably alpha-farnesene and beta-farnesene, with the molecular formula C15H24. These acyclic sesquiterpenes are produced by a wide range of plants as components of essential oils and stored in glands or secretory tissues. Farnesene is a precursor in the biosynthesis of longer terpenoids via the mevalonate pathway, derived from farnesyl pyrophosphate by farnesene synthase.

Occurrence and roles: In apples, alpha-farnesene is a major volatile emitted from the peel and contributes to the characteristic fruit aroma; beta-farnesene is widespread in plant essential oils. Biologically, farnesenes function as signaling compounds in plant defense: they can attract natural enemies of herbivores, and E-beta-farnesene serves as an alarm pheromone for many aphids.

Applications: In flavor and fragrance industries, farnesene is used as a scent component. In agriculture, synthetic E-beta-farnesene is explored as part of pest management strategies to manipulate aphid behavior and enhance biological control.

See also: Terpenes, sesquiterpenes, essential oils.