Δ-capnellene, also referred to simply as capnellene in the literature, is a monounsaturated hydrocarbon of the molecular formula CH. It features a tricyclic skeleton, a geminal dimethyl group, a tertiary methyl group, and an exocyclic methylene group.
Capnellene is also a sesquiterpene, a class of terpenes that are natural semiochemicals. However, it is a non-isoprenoid sesquiterpene, meaning that unlike most sesquiterpenes its structure is not based on a repeated isoprene unit. Capnellene is the presumed biosynthetic precursor to the capnellanols, a group of alcohols based on the capnellene skeleton that are also produced by Capnella imbricata, however the biosynthesis of these compounds has not yet been elucidated.