3. KOBA-TERPENOID.pdf

7/23/2019 3. KOBA-TERPENOID.pdf

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KIMIA ORGANIK BAHAN ALAM

Terpenoid

Written by Dante Alighiri



UNIVERSITAS NEGERI SEMARANG

DEFINITIONS

1

The simple isoprene unit is the basis of an

enormous range and a variety of chemical

structures which we know as TERPENOIDS

(TERPENES)

Isoprene is a conjugated diene. It is a colorless liquid made

by destructive distillation of rubber or from petroleum, and

used to make synthetic rubber. It is the basic unit of plant

products, including carotenoids, sterols, and terpenes

(terpenoids)




DEFINITIONS

1

Carbon 1 is called the head of the molecule; carbon 4 iscalled the tail.

Since the isoprene molecule has five carbon atoms, thenumber of carbon atoms in the molecule of aterpene/terpenoid is a multiple of five

For identification purposes, the five carbon atoms in

isoprene are numbered as follows:




DEFINITIONS

1

Terpenes are hydrocarbons, whereas Terpenoids contain

oxygen.

Organic chemists increasingly use the words terpene and

terpenoid interchangeably.

What is difference between TERPENES andTERPENOIDS?

Myrcene

(constituent of bayberry oil)

Geraniol

(constituent of geranium oil)Geranium flower (Geranium L.)

Bayberry fruit (Myrica gale L.)




PURPOSES

&

FUNCTIONS

2

In nature, terpenoids serve a variety of purposes

including defence, signaling and as key agents in

metabolic processes

Terpenoids have been used in perfumery,cosmetics , and medicine for thousands of years

and are still extracted from natural sources for

these uses.


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CLASSIFICATION

3

Terpenoids are defined as materials with molecular

structures containing carbon backbones made up ofisoprene (2-methylbuta-1,3-diene) units.

Isoprene contains five carbon atoms and therefore, the

number of carbon atoms in any terpenoid is multiple of 5.

The generic name terpene (terpenoids/monoterpenoids)

was originally applied to the hydrocarbons found in

turpentine.

The suffic – ene indicating the presence of olefinic bonds.

Each of these materials contain two isoprene units, hence

10 carbon atoms.

Related materials containing 20 carbon atoms are named

as diterpenes (diterpenoids).

The most basic members of the family, i.e. those containing

only one isoprene unit, came to be known as

hemiterpenoids.



CLASSIFICATION

3

Name No. of isoprene units No. of carbon atoms

Hemiterpenoids 1 5

Monoterpenoids 2 10

Sesquiterpenoids 3 15

Diterpenoids 4 20

Sesterterpenoids 5 25

Triterpenoids 6 30

Tetraterpenoids 8 40

Polyisoprenoids

(Polyterpenoids)

>8 >40

Steroids 6 30

Caretenoids 8 40



ISOPRENE RULE

4

Terpenoids as chemicals containing a carbon skeleton formedby the joining together of isoprene units.

Isoprene, the building block of terpenoids is 2-methylbuta-1,3-

diene.

Two or more isoprene molecules are linked to one

another. Linking between two isoprene molecules could

occur in three ways, given that the head and the tail of the

molecule are primarily involved in the linking

head-to-tail type to produce a monoterpenoids backbone



ISOPRENE RULE

4

1.The head of one isoprene molecule could link with thehead of another isoprene molecule.

This link is called a head-to-head or 1-1 link

2. The head of one isoprene molecule could link with the tail

of another isoprene molecule.

This link is called a head-to-tail or 1-4 link



ISOPRENE RULE

4

head-to-head, tail-to-tail, head-to-tail, by far the commonest

fusion is head-to-tail.

Occasionally, a tail-to-tail coupling occurs. This is characteristic

feature of steroids and caretonoids.

The hypothetical head-to-head fusion does not occur.

3. The tail of one isoprene molecule could link with the tail ofanother isoprene molecule.

This link is called a tail-to-tail or 4-4 link



ISOPRENE RULE

4

Cyclic terpenes also contain links that are neither 1-1,1-4, nor 4-4, which are called crosslinks. Isoprene rule

states that, in most naturally occurring terpenes, there

are no 1-1 or 4-4 links

Mrycene

Limonene

Retinol



ISOPRENE RULE

4 β -carotene

After formation of the C5n skeleton, the chain may be folded

to produce rings and functionalized by the introduction of

oxygen or other heteroatom



ISOPRENE RULE

4



NOMENCLATURE

5

Families of terpenoids possessing the same skeleton

are named after a principal member of that family,

usually either the most common or the first to have

been discovered. Charts of these names are given in

Devon and Scott’s dictionary.

The name an individual terpenoid, it is customary to

use the IUPAC or CAS systems of nomenclature.

It is often more convenient to use either a trivialname or a semi-systematic name derived from the

terpenoid structural family to which the material in

question belongs.



5

As an example of the co-existence of systematic, semi-

systematic and trivial names.

The monoterpenoid ketone, carvone. Carvone occurs in

both enantiomeric forms in nature:

1. leavo-form in spearmint

2. dextro-form in caraway

Trivial name: carvone is derived from the Latin name for

caraway, Carum carvi

Systematic name: the basic carbon skeleton is that of 1-

isopropyl-4-methylcyclohexane

Semi-systematic name: This skeleton is very common in

nature and is particularly important in the genus

Mentha, which includes various types of mint, since it

forms the backbone of most of the important

components of mint oils. The skeleton has therefore

been given the name p-menthane

NOMENCLATURE




5

Trivial : carvone

Systematic : 1-methyl-4-(1-methylethenyl)cyclohex-1-

ene-6-one

Semi-systematic : p-menthan-1,8-dien-6-one

To classify it, we would say it was an unsaturated ketone of

the p-menthane family of monoterpenoids

NOMENCLATURE




5

Greek letters are used in various ways to distinguish

between isomeric terpenoids. They may indicate theorder in which the isomers were discovered or their

relative abundance in the oil. For instance:

1. α-pinene is the most significant component of

turpentine, usually comprising almost there quarters of

the oil by weight.

2. β -pinene is the next significant component of

turpentine

NOMENCLATURE




5

In the case of cyclic terpenoids, the letters α, β , and γ

often refer to the location of the double bond in isomericolefins.

1. The letters α: indicates an endocyclic trisubstituted

double bond

2. The letters β : indicates an endocyclictetrasubstituted olefinic bond

3. The letters γ: indicates an exocyclic methylene

function

NOMENCLATURE




5

NOMENCLATURE




TERPENOIDS

IN

NATURE

6

1. Vitamin A, or retinol, is the precusor for the pigment in eyes

which detects light and is therefore responsible for the

senses of sight.

Functional Terpenoids as play key part in the metabolicprocesses of the organism in which they are produced

2. Vitamin E, or tocopherol, is an important antioxidant which

prevents oxidative damage to cell




TERPENOIDS

IN

NATURE

6

3. Vitamin D2, also known calciferol, regulates calcium

metabolism in the body and is therefore vital for thebuilding and maintenance of bone.

4. Chlorophyll-a is green pigment found, for example, in plant

leaves and is a key factor of photosynthesis through which

atmospheric carbon dioxide is converted to glucose

3

4




TERPENOIDS

IN

NATURE

6

1. Many plants, when damaged, exude resinous

materials as defence mechanism. Rosin is produced as

a physical barrier to infectious organisms, by pine

trees when the bark is damaged. Similarly, rubber is adefensive secretion.

The shrub Commiphora abyssinica (Commiphora

habessinica, myrrh tree, Arabian myrrh, Yeman myrrh )

produces a resin which contains a number of

antibacteria and antifungal compounds. One of theseis the eudesmane derivative

Defence Terpenoids as terpenoid chemicals to protect

themselves via production of resins




6

The role of the resin is to seal the wound and prevent

bacteria and fungi from entering and damaging theplant. The resin has a pleasant odour and so was put

the use by man as perfume ingredient. It is known as

myrrh. Because of its antimicrobial properties, myrrh

was also used as an antiseptic and preservative

material, for instance, in the embalming of corpses.2. Frankincense, derived from trees of the genus

Boswellia, is another such resin and has been used in

religious rites for thousands of years.

TERPENOIDS

IN

NATURE

Boswellia sacra




6

3. Bufotalin, also known is a cardiac glycoside whichfunction as a heart stimulant. It is produced by toads

in order to prevent other animals from preying on

them; would be predators soon learn that toads do

not make good food.

TERPENOIDS

IN

NATURE




6

TERPENOIDS

IN

NATURE

4. Similarly, many plants produce terpenoids makingthem unpalatable to insects which would otherwise

eat their foliage.

Azadirachtin which is produced by Melia azadirachta

(white cedar, chinaberry, mindi, renceh, cakra-cikri)

and also by the Indian neem tree (mimba), Azadiractaindica.




6

5. Warburganal which is produced by plants of the genus

Warburgia.Warburganal contain two aldehyde functions and one of

these is α, β -unsaturated. Thus, it is capable of undergoing

triple alkylation of nucleophilic materials such as the

nitrogen atoms of proteins and nucleic acids. This property

makes it a skin sensitiser (i.e. a material which can induce an

allergic reaction in some subjects upon repeated exposure)and carcinogen. It is therefore a doubly effective deterrent

because of its unpleasant taste and high toxicity. In the figure

the arrow indicate the three potential sites of nucleophilic

attack.

TERPENOIDS

IN

NATURE




6

A. If the communication is between different parts of

the same organism, the messenger is referred to as a

hormone.

1. Giberellic acid is a hormone used by plants and fungito control their rate of growth

2. Testosterone and oestrone are mamalian sex

hormones. Testosterone is a male hormone and

oestrone, a female.

TERPENOIDS

IN

NATURE

Terpenoids are also used as chemical messengers. It called

as Communication Terpenoids




6

B. Chemicals that carry signals from one organism toanother are known as semiochemicals.

These can be grouped into two main classes.

TERPENOIDS

IN

NATURE Semiochemicals

Pheromones

Allelochemicals




6

1. If the signal is between two members of the samespecies, the messenger is called a pheromones.

Pheromones carry different type of information.

TERPENOIDS

IN

NATURE

Not all species use pheromones. In those which do, some

may use only one or two pheromones while others, inparticular the social insects such as bees, ants, and

termites, use an array of chemical signals to organize most

aspects of their lives.

Sex pheromones are among the most widespread. Malemoths can detect female by smell at a range of many

miles.




6

Androst-16-en-3-ol is a porcine sex pheromone and the

compound which produces “boar taint” in pork. (Boar taint

is flavour found in the meat of boars but not of sows). It is

produced by boars and is released in a fine aerosol when

the boar salivates and champs his jaws. When the sow

detects pheromone in air, she immediately adopts what is

known as “the mating stance” in readines for the boar.TERPENOIDS

IN

NATURE

Grandisol is a sex attractant for the male boll weevil, a

serious pest for cotton growers.




6

Ants and termites use trail pheromones to mark a path

between the nest and a food source. This explains why

ants are often seen walking in single file over long

distances. One such trail pheromone is neocembrene-A

which is produced and used by termites of the Australian

species Nasutitermes exitiosus

TERPENOIDS

IN

NATURE




6

The social insects also use alarm, aggregation, dispersal,

and social pheromones to warn of danger and to control

group behaviour. For example, d -limonene is an alarm

pheromone of some Australian termites and lineatin is the

aggregation pheromone of Thrypodendron lineatum.

So, exposure to these two terpenoids will produceopposite reactions in their target species, repulsion in the

first case and attraction in the second.

TERPENOIDS

IN

NATURE




6

2. Chemicals which carry messages between members of

different species are known as allelochemicals.

Within this group, allomones benefit the sender of the

signal, kairomones its receiver and with synomones

both the sender and receiver benefit.

TERPENOIDS

IN

NATURE Alleochemicals

Allomones

Kairomones

Synomones




6

d -limonene in the latex exuded by trees of the species

Araucaria bidwilli . These tree are protected from termite

attack because the d -limonene they produce is an alarm

pheromone for termites that live in the area. Similarly,

antifeedants could be considered to be allomones since

the signal generator, the plant, receives the benefit of not

being eaten.

TERPENOIDS

IN

NATURE

Camphor and d -limonene are allomones in the the trees

which produce them are protected from insect attack bytheir presence.




6

Myrcene is a kairomones , in that it is produced by the

penderosa pine and its presence attracts the females ofthe bark beetle, Dendroctonous brevicomis.

Geraniol is found in the scent of many flowers such as the

rose. Its presence attracts insects to the flower and it can

be classified as a synomone since the attracted insect

finds nectar and the plant obtains a pollinator.

TERPENOIDS

IN

NATURE




6

One terpenoid which has an unsual signaling property is

nepetalactone. This is actually a mixture of two isomers.

The major being the trans, trans-isomer (1.2) and the minor the

trans, cis-isomer (1.3). Neptalactone is the principal component

of the oil catnip or cat mint (Nepta cataria), constituting 70-90%

of the oil. It is an insect repellent, which is probably why theplant produces it. However, it has a surprising effect on all

felines, from domestic cats to lions and tigers, in that it induces

grooming and rolling behaviour in them. This is probably purely

coincidental as it is hard to see what benefit this would be to the

plant.

TERPENOIDS

IN

NATURE




7

THE USE

OF

TERPENOIDS

Many commercial uses of terpenoids reflect their natural

uses. Those that are produced in nature because of theirbiological activity may well find commercial use as drugs or

pest control agents.

α-santonin is extracted from Levant wormseed, Artemisia

maritima, for use as an anthelmintic.

The poisonous nature of foxglove is due to the presence of

terpenoid glycosides which have strong stimulant action on

heart muscle. Digitoxin is a glycoside of digitoxigenin andit extracted from foxglove for use in treatment of certain

heart conditions.




7

The odorous terpenoids are, of course, used as fragrance

ingredients in cosmetics, toiletries, and house-holdproducts.

Cineole, extracted from various eucalyptus species, serves

both purposes since it is used in perfumery as well as a

nasal decongestant.

Rubber is a polymer of isoprene which is produced in the

rubber tree as a defensive secretion but is widely used by

humans because of its elastic properties.

Turpentine has a long history of use as a solvent,particularly for paints and, similarly, lac resin as varnish.

Nowadays, turpentine is also used as a feedstock for the

synthesis of other materilas of commercial interest, in

addition to a wide variety of fragrance ingredients.

THE USE

OF

TERPENOIDS



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