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 A
Names
IUPAC name
(1E,5E,8S)-1,5-dimethyl-8-(prop-1-en-2-yl)cyclodeca-1,5-diene
Other names
  • (−)-Germacrene A
  • (E,E)-Germacra-3,9,11-triene
  • (1E,5E,8S)-1,5-dimethyl-8-(1-methylethenyl)-1,5-cyclodecadiene
  • (S-(E,E))-1,5-dimethyl-8-(1-methylethenyl)-1,5-cyclodecadiene
Identifiers
3D model (JSmol)
6500908 (A) 1864177 (D)
ChEBI
ChEMBL
ChemSpider
KEGG
  • InChI=1S/C15H26/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,12,15H,5,7-8,10-11H2,1-4H3/b13-6+,14-9+/t15-/m0/s1 ☒N
    Key: YDLBHMSVYMFOMI-SDFJSLCBSA-N ☒N
  • InChI=1/C15H26/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,12,15H,5,7-8,10-11H2,1-4H3/b13-6+,14-9+/t15-/m0/s1
    Key: YDLBHMSVYMFOMI-SDFJSLCBBV
  • A: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,15H,1,5,7-8,10-11H2,2-4H3/b13-6+,14-9+/t15-/m1/s1
    Key: XMRKUJJDDKYUHV-DFSVIBJJSA-N
  • D: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h7-8,10,12,15H,3,5-6,9,11H2,1-2,4H3/b10-8-,14-7-
    Key: GAIBLDCXCZKKJE-BZXLUOIMSA-N
  • E: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,11,14-15H,1,5,7-8,10H2,2-4H3/b11-9+,13-6+
    Key: OAOGSSAAVUPEKA-BMCYRRRCSA-N
  • C/C/1=C\CC/C(=C/C[C@H](CC1)C(C)C)/C
  • A: C/C/1=C\CC/C(=C/C[C@@H](CC1)C(=C)C)/C
  • B: C/C/1=C\CC/C(=C/CC(=C(C)C)CC1)/C
  • C: C/C/1=C\CC/C(=C/C=C(\CC1)/C(C)C)/C
  • E: CC\1CC/C=C(/CCC(/C=C1)C(=C)C)\C
Properties
C15H24
Molar mass 204.35 g/mol
Density 0.793 g/mL
Boiling point 236.4 °C (457.5 °F; 509.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Germacrene D
Names
IUPAC name
(S,1Z,6Z)-8-isopropyl-1-methyl-5-methylidenecyclodeca-1,6-diene
Other names
1-methyl-5-methylene-8-(1-methylethyl)-1,6-cyclodecadiene
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h7-8,10,12,15H,3,5-6,9,11H2,1-2,4H3/b10-8-,14-7-/t15-/m0/s1
    Key: GAIBLDCXCZKKJE-ACWLMNNXSA-N
  • InChI=1/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h7-8,10,12,15H,3,5-6,9,11H2,1-2,4H3/b10-8-,14-7-/t15-/m0/s1
    Key: GAIBLDCXCZKKJE-ACWLMNNXBY
  • C/C/1=C/CCC(=C)/C=C\[C@@H](CC1)C(C)C
Properties
C15H24
Molar mass 204.35 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Structures

edit

Germacrene has five isomers.

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

Natural occurrences

edit

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

edit
  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

edit

General

edit
  • 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

edit

Germacrene D

edit