Germacrenes are a class of volatile organic hydrocarbons, specifically, sesquiterpenes. Germacrenes are typically produced in a number of plant species for their antimicrobial and insecticidal properties, though they also play a role as insect pheromones. Two prominent molecules are Germacrene A and Germacrene D.
Germacrene has five isomers - Germacrene A, B, C, D, and E. The essential oil of the red deadnettle (Lamium purpureum) is characterized by its high contents of Germacrene D, as is Clausena anisata.
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