Zingiberene is a monocyclic

sesquiterpene Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modificatio ...

that is the predominant constituent of the oil of

ginger Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice A spice is a seed, fruit, root, bark, or other plant substance primarily used for flavoring or coloring food. Spices ...

(''Zingiber officinale''), from which it gets its name. It can contribute up to 30% of the

essential oils An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

in ginger

rhizomes In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

. This is the compound that gives ginger its distinct flavoring.

Biosynthesis

Zingiberene is formed in the

isoprenoid pathway The mevalonate pathway, also known as the isoprenoid pathway or HMG-CoA reductase pathway is an essential metabolic pathway present in eukaryotes, archaea, and some bacteria. The pathway produces two five-carbon building blocks called isopentenyl ...

from

farnesyl pyrophosphate Farnesyl pyrophosphate (FPP), also known as farnesyl diphosphate (FDP), is an intermediate in the biosynthesis of terpenes and terpenoids such as sterols and carotenoids. It is also used in the synthesis of CoQ (part of the electron transport cha ...

(FPP). FPP undergoes a rearrangement to give

nerolidyl diphosphate Nerolidol, also known as peruviol and penetrol , is a naturally occurring sesquiterpene alcohol. A colorless liquid, it is found in the essential oils of many types of plants and flowers. There are four isomers of nerolidol', which differ in the ...

. After the removal of

pyrophosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among other ...

, the ring closes leaving a carbocation on the tertiary carbon attached to the ring. A 1,3-hydride shift then takes place to give a more stable allylic carbocation. The final step in the formation of zingiberene is the removal of the cyclic allylic proton and consequent formation of a double bond.

Zingiberene synthase Zingiberene synthase (EC 4.2.3.65, α-zingiberene synthase, ZIS) is an enzyme with systematic name (2''E'',6''E'')-farnesyl-diphosphate diphosphate-lyase (zingiberene-forming). This enzyme catalyses the following chemical reaction : (2''E'',6''E ...

is the enzyme responsible for catalyzing the reaction forming zingiberene as well as other mono- and sesquiterpenes.

References

{{Reflist Sesquiterpenes Alkene derivatives Ginger Cyclohexadienes

Biosynthesis

See also

References