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.

Structures

Germacrene has five isomers.

Germacrene isomers
Germacrene A Germacrene B Germacrene C Germacrene D Germacrene E
Germacrene A Germacrene B Germacrene C Germacrene D Germacrene E

Natural occurrences

The essential oils of red deadnettle (Lamium purpureum)[1] and hedgenettles (genus Stachys)[2] are characterized by their high contents of germacrene D, as is Clausena anisata. It is also a major component of patchouli oil.

References

  1. ^ Flamini, G.; Cioni, P. L.; Morelli, I. (2005). "Composition of the essential oils and in vivo emission of volatiles of four Lamium species from Italy: L. purpureum, L. hybridum, L. bifidum and L. amplexicaule". Food Chemistry. 91 (1): 63–68. doi:10.1016/j.foodchem.2004.05.047.
  2. ^ Morteza‐Semnani, K.; Akbarzadeh, M.; Changizi, Sh. (2005-11-01). "Essential oils composition of Stachys byzantina, S. inflata, S. lavandulifolia and S. laxa from Iran". Flavour and Fragrance Journal. 21 (2): 300–303. doi:10.1002/ffj.1594.

Further reading

General

  • Adio, A. M. (2009). "Germacrenes A–E and related compounds: thermal, photochemical and acid induced transannular cyclizations". Tetrahedron. 65 (8): 1533–1552. doi:10.1016/j.tet.2008.11.050.

Germacrene A

Germacrene D