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
![ZingibereneBiosyn](https://upload.wikimedia.org/wikipedia/commons/6/6d/ZingibereneBiosyn.svg)
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.
See also
*
Gingerol
Gingerol ( gingerol) is a phenolic phytochemical compound found in fresh ginger that activates spice receptors on the tongue. It is normally found as a pungent yellow oil in the ginger rhizome, but can also form a low-melting crystalline solid. T ...
* sequiphellandrene
References
{{Reflist
Sesquiterpenes
Alkene derivatives
Ginger
Cyclohexadienes