{{#invoke:Infobox|infobox}} Longifolene synthase (EC 4.2.3.58) is an enzyme with system name (2E,6E)-farnesyl-diphosphate diphosphate-lyase (longifolene-forming).<ref>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref> This enzyme catalyses the following chemical reaction

(2E,6E)-farnesyl diphosphate <math>\rightleftharpoons</math> longifolene + diphosphate

This enzyme forms alpha-longipinene, longicyclene and traces of other sesquiterpenoids.