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Chapter 12 · The Balm of the Trees - Terpenes
12
5 Terpenoids include hydrocarbons, but
also alcohols, aldehydes, ketones and
carboxylic acids. They can have acyclic
or cyclic structures. There are mono-, biand tricyclic terpenes.
5 Large quantities of terpenes are obtained
from turpentine oils, a liquid that can be
extracted from conifers. Depending on
the starting material and procedure, a
distinction is made between wood, gum
and sulfate turpentine. When distilling
the turpentine, the solid colophonium
remains.
5 The acyclic monoterpenes include the
hydrocarbons β-myrcene and ocimene,
the alcohols linalool, geraniol and nerol
and the aldehyde citral obtained from
lemongrass oil. Citral is the starting
compound for many other terpenes, e.g.
for menthol and β-ionone.
5 The simplest monocyclic monoterpene is
limonene, often referred to as dipentene.
It is an important platform chemical
e.g. for the production of terpineols,
para-cymene or dihydrocarvone.
5 The bicyclic monoterpenes include
compounds, which, in addition to a
six-membered ring, also contain a
three-membered ring (e.g. 2-carene), a
four-membered ring (e.g. the pinenes) or
a five-membered ring (e.g. camphene).
5 The two most important pinenes, α- and
β-pinene, are the main components of
turpentine oils and therefore easily and
inexpensively accessible. They are also
important platform chemicals. The acyclic
β-myrcene is produced by pyrolysis of the
pinenes.
5 Camphor can be produced from
camphene via the intermediate
borneol, and is used, for instance, in the
production of celluloid or mothballs.
5 The approximately 8000 known
sesquiterpenes consist of three
isoprene units. These include the acyclic
farnesenes, but also cyclic compounds
such as the ginger-tasting zingiberene,
the C11-membered ring alcohol humulol,
the tricyclic compounds taurine and
artemisinin.
composed of six isoprene units. The acyclic
molecule consists of two head-tail-linked
C 15 H 25 units, which are linked together in the
middle in a tail–tail manner. It occurs in codliver oil of fish, in particularly high concentrations in the cod-liver oil of sharks (genus:
squalus). It is widespread in nature and is
also found in rapeseed oil, olive oil, wheat
germ oil and cottonseed oil. Squalene is also
found in humans, e.g. in skin lipids and blood
serum. Squalene is as well an intermediate
stage in the biosynthesis of steroids, such as
estrogens or testosterone (7 Chap. 16), cholesterol and vitamin D (7 Chap. 17).
5 The last molecule in . Fig. 12.12 is
β,β-carotene. It is an important representative of the more than 150 known tetraterpenes. The name of the compound derives
from the carrot (lat. daucus carota), in which
the orange–red carotene occurs in larger
quantities. Carotenes and their derivatives,
carotenoids, are also frequently found in
other fruits, roots and leaves. In the leaves of
plants, the carotenoids serve as color filters
for photosynthesis. When the green chlorophyll of the leaves is degraded in autumn, the
yellow, red and brown coloring of the carotenoids remains, which degrade more slowly.
Carotene is an important precursor to the
formation of vitamin A and is therefore also
known as “provitamin A”. Humans ingest carotenes with their food. They act as “antioxidants” and have a cell protecting effect.
The polyterpenes, which are composed of n
isoprene units, are described in more detail in
7 Chap. 13.
Summary (Take-Home Messages)
5 Terpenes are subject to the “isoprene
rule” established by Otto Wallach, i.e.
they are formally composed of isoprene
units. They are also called terpenoids or
isoprenoids.
5 Depending on the number n of isoprene
units, a distinction is made between
monoterpenes (n = 2), sesquiterpenes
(n = 3), diterpenes (n = 4), triterpenes
(n = 6) and tetraterpenes (n = 8). If n is
very high, we use the term polyterpenes.
Chapter 12 · The Balm of the Trees - Terpenes
12
5 Terpenoids include hydrocarbons, but
also alcohols, aldehydes, ketones and
carboxylic acids. They can have acyclic
or cyclic structures. There are mono-, biand tricyclic terpenes.
5 Large quantities of terpenes are obtained
from turpentine oils, a liquid that can be
extracted from conifers. Depending on
the starting material and procedure, a
distinction is made between wood, gum
and sulfate turpentine. When distilling
the turpentine, the solid colophonium
remains.
5 The acyclic monoterpenes include the
hydrocarbons β-myrcene and ocimene,
the alcohols linalool, geraniol and nerol
and the aldehyde citral obtained from
lemongrass oil. Citral is the starting
compound for many other terpenes, e.g.
for menthol and β-ionone.
5 The simplest monocyclic monoterpene is
limonene, often referred to as dipentene.
It is an important platform chemical
e.g. for the production of terpineols,
para-cymene or dihydrocarvone.
5 The bicyclic monoterpenes include
compounds, which, in addition to a
six-membered ring, also contain a
three-membered ring (e.g. 2-carene), a
four-membered ring (e.g. the pinenes) or
a five-membered ring (e.g. camphene).
5 The two most important pinenes, α- and
β-pinene, are the main components of
turpentine oils and therefore easily and
inexpensively accessible. They are also
important platform chemicals. The acyclic
β-myrcene is produced by pyrolysis of the
pinenes.
5 Camphor can be produced from
camphene via the intermediate
borneol, and is used, for instance, in the
production of celluloid or mothballs.
5 The approximately 8000 known
sesquiterpenes consist of three
isoprene units. These include the acyclic
farnesenes, but also cyclic compounds
such as the ginger-tasting zingiberene,
the C11-membered ring alcohol humulol,
the tricyclic compounds taurine and
artemisinin.
composed of six isoprene units. The acyclic
molecule consists of two head-tail-linked
C 15 H 25 units, which are linked together in the
middle in a tail–tail manner. It occurs in codliver oil of fish, in particularly high concentrations in the cod-liver oil of sharks (genus:
squalus). It is widespread in nature and is
also found in rapeseed oil, olive oil, wheat
germ oil and cottonseed oil. Squalene is also
found in humans, e.g. in skin lipids and blood
serum. Squalene is as well an intermediate
stage in the biosynthesis of steroids, such as
estrogens or testosterone (7 Chap. 16), cholesterol and vitamin D (7 Chap. 17).
5 The last molecule in . Fig. 12.12 is
β,β-carotene. It is an important representative of the more than 150 known tetraterpenes. The name of the compound derives
from the carrot (lat. daucus carota), in which
the orange–red carotene occurs in larger
quantities. Carotenes and their derivatives,
carotenoids, are also frequently found in
other fruits, roots and leaves. In the leaves of
plants, the carotenoids serve as color filters
for photosynthesis. When the green chlorophyll of the leaves is degraded in autumn, the
yellow, red and brown coloring of the carotenoids remains, which degrade more slowly.
Carotene is an important precursor to the
formation of vitamin A and is therefore also
known as “provitamin A”. Humans ingest carotenes with their food. They act as “antioxidants” and have a cell protecting effect.
The polyterpenes, which are composed of n
isoprene units, are described in more detail in
7 Chap. 13.
Summary (Take-Home Messages)
5 Terpenes are subject to the “isoprene
rule” established by Otto Wallach, i.e.
they are formally composed of isoprene
units. They are also called terpenoids or
isoprenoids.
5 Depending on the number n of isoprene
units, a distinction is made between
monoterpenes (n = 2), sesquiterpenes
(n = 3), diterpenes (n = 4), triterpenes
(n = 6) and tetraterpenes (n = 8). If n is
very high, we use the term polyterpenes.