Bergamotene

Not to be confused with bergamottin.

Bergamotenes are a group of isomeric chemical compounds with the molecular formula C₁₅H₂₄. The bergamotenes are found in a variety of plants, particularly in their essential oils.

Bergamotenes

α-cis-bergamotene α-trans-bergamotene
β-cis-bergamotene β-trans-bergamotene
Names
IUPAC names (α): 2,6-Dimethyl-6-(4-methylpent-3-enyl)bicyclo[3.1.1]hept-2-ene (β): 6-Methyl-2-methylidene-6-(4-methylpent-3-en-1-yl)bicyclo[3.1.1]heptane
Identifiers
CAS Number	(α): 17699-05-7 (α-trans): 13474-59-4 (α-cis): 23971-87-1 (β): 6895-56-3 (β-trans): 15438-94-5 (β-cis): 15438-93-4
3D model (JSmol)	(α): Interactive image (β) (β): Interactive image
ChEBI	(α-trans): CHEBI:62756 (α-cis): CHEBI:61679 (β-cis): CHEBI:61678
ChemSpider	(α-trans): 78115
KEGG	(α-trans): C20811 (α-cis): C19735 (β-cis): C19737
PubChem CID	(α-trans): 6429302 (α-cis): 6429303 (β-trans): 12300073 (β-cis): 12300069
UNII	(α-trans): 599TK2712C (α-trans) Y (β): 2H330CKD1Z Y
CompTox Dashboard (EPA)	(α-trans): DTXSID901017570
SMILES (α): CC1=CCC2CC1C2(C)CCC=C(C)C (β) (β): CC(=CCCC1(C2CCC(=C)C1C2)C)C
Properties
Chemical formula	C15H24
Molar mass	204.357 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

There are two structural isomers, α-bergamotene and β-bergamotene, which differ only by the location of a double bond. Both of these isomers have stereoisomers, the most common of which are known as the cis and trans-isomers (or endo- and exo-isomers).

α-Bergamotene is found in the oils of carrot, bergamot, lime, citron, cottonseed, and kumquat.^[1][2]

Pheromones

The bergamotenes are pheromones for some insects. For example, β-trans-bergamotene is a pheromone for the wasp Melittobia digitata.^[3] Plants can defend themselves against attack by herbivorous insects by producing pheromones such as bergamotenes that attract predators of those herbivores.^[4][5] In a more complex relationship, the tobacco plant Nicotiana attenuata emits α-trans-bergamotene from its flowers at night to attract the tobacco hawk moth (Manduca sexta) as a pollinator; however, during the day the leaves produce α-trans-bergamotene to lure predatory insects to feed on any larvae and eggs that the pollinator may have produced.^[6][7]

Biosynthesis

All the bergamotenes are biosynthesized from farnesyl pyrophosphate^[8] via a variety of enzymes including exo-alpha-bergamotene synthase, (+)-endo-beta-bergamotene synthase, (-)-endo-alpha-bergamotene synthase, and others. Bergamotenes, in turn, are intermediates in the biosynthesis of more complex chemical compounds. For example, β-trans-bergamotene is a precursor in the biosynthesis of fumagillin, ovalicin, and related antibiotics.^[8][9]