Terpenes and Terpenoids

Terpenes - class of >20,000 compounds containing carbon atoms in multiples of five

Terpenoids - oxygen-containing terpenes (alcohols, ketones, aldehydes)

(kereviz)

(zencefil)

The name "terpene" is derived from the word "turpentine" (terebentin-reineden elde edilir)

Terpenes and terpenoids are the primary constituents of theessential oilsof many types of plants and flowers.Essential oils : bitkilerdeki sellloz ve niasta dndaki ou kez uucu olan belli bir tad/kokuya sahip bileikler)

rose oil

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The basic molecular formulae of terpenes are multiples of that, (C5H8)nwhere n is the number of linked isoprene -Isoprene - 2-methyl-1,3-butadiene- units. This is called theisoprene ruleor theC5 rule.

Compounds containing carbon atoms in multiples of 5 suggest a C5 building block - isoprene units linked in a head-to-tail fashion

Ancak unutulmamaldr ki molekller byyp halkalatka biyosentezler bakalamalara yol aabilirler. Retrosentezlerle baa gidilir.

Head - branched end of isoprene

Tail - unbranched end of isoprene

2-methyl-1,3-butadiene

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Finding the isoprene building block - cyclic compounds

Finding the isoprene building block - sesquiterpenes (C15)

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Finding the isoprene building block - triterpenes (C30) -

Squalene has a natural and vital part in the synthesis of all plant and animalsterols, including cholesterol, steroid hormones, and vitamin D in the human body

Finding the isoprene building block - tetraterpenes (C40)

Lycopene is responsible for the red color in tomatoes and watermelon

-carotene is the compound that causes carrots and apricots to be orange

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Lycopene's elevenconjugated double bondsgive it its deep red color and are responsible for itsantioxidantactivity.

Biosynthesis of Terpenes

Biological isoprene - isopentenyl pyrophosphate (3-methyl-3-butenylpyrophosphate). Enzimlerle izomerizasyona urar. zomerizasyon rn yeni bir isopentenilpirofosfat ile reaksiyonda monoterpen ieren pirofosfat trevi oluturur. Bu son trev doal koullarda ester hidrolizine urar ve bir terpenoid olan geraniol verir.

Aldol cond

Enzimle hid.

Tioesterden alkole

SN2

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RULE - isopentenyl pyrophosphate and dimethylallyl pyrophosphate are the C5 building blocks for the biosynthesis of terpenes

Elimination of a proton from a carbocation intermediate generates a double bond (E1 reaction)

Geranyl pyrophosphate - C10 building block for many biological monoterpenes

Geranyl pyrophospate ester hid ile geraniol verir.

Isopentenyl pyrophosphate is only one of the necessary reagents for the biosynthesis of terpenes dimethylallyl pyrophosphate, a C5 isomer, is also necessary:

Add. of H+

elimination of a proton

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Hemiterpenesconsist ofa single isopreneunit. Isoprene itself is considered the only hemiterpene, but oxygen-containing derivatives are hemiterpenoids such as prenol(found in citrus fruits, cranberry, grapes, raspberry, blackberry, tomato, white bread) andisovaleric acid(found in inessential oils).

Monoterpenes consist oftwo isopreneunits and have the molecular formula C10H16. Examples of monoterpenes are:geraniol,limoneneand terpineol.

Sesquiterpenes consist ofthree isopreneunits and have the molecular formula C15H24. Examples of sesquiterpenes are:humulene,farnesenes, farnesol.

Prenol

isovaleric acid

limonene

a strong smell of oranges

humulene

found in theessential oilsofHumulus lupulus

terpineol

found in pine oil

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Sesterterpenes, terpenes having 25 carbons andfive isopreneunits, are rare relative to the other sizes. An example of a sesterterpene isgeranylfarnesol.

Triterpenes consist ofsix isopreneunits and have the molecular formula C30H48. The linear triterpenesqualene, the major constituent ofshark liver oil.

Tetraterpenescontaineight isopreneunits and have the molecular formula C40H64. Biologically important tetraterpenes include the acycliclycopene, the monocyclicgamma-carotene, and the bicyclicalpha-andbeta-carotenes.

Polyterpenesconsist of long chains ofmany isopreneunits. Naturalrubberconsists of polyisoprene in which the double bonds arecis.

Diterpenes are composed offour isopreneunits and have the molecular formula C20H32. Examples arecafestol,kahweol,cembreneandtaxadiene(precursor oftaxol). Diterpenes also form the basis for biologically important compounds such asretinol,retinal, andphytol. They are known to be antimicrobial and antiinflammatory.

taxol used incancer chemotherapy

Pasifik porsuk aac kabuklarndan

Taxadiene from enzymes

Retinol is one of the forms ofvitamin A

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Terpenler HALKA SAYISINA gre de snflandrlabilirler:

Asiklik, monosiklik, bisiklik, trisiklik (2Z)-3,7-dimethyl-2,6-octadien-1-ol

Terpenlerde isimlendirme: IUPAC kurallar yansra zel okumalar da sz konusudur.

Asiklik terpen rnekleri:

Kuyruk

ba

(trans)-3,7-Dimethyl-2,6-octadien-1-ol

Ald turevi citral-a

(2Z)-3,7-dimethyl-2,6-octadien-1-ol

Ald turevi citral-b

Monosiklik Monoterpen rnekleri: menthol

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Mirisen

fromparsley..

menthol

Carvone

Kimyon ya

Thymol

87.cdx88.cdx

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Bisiklik terpenlerin IUPAC okunmas:

3,7,7-trimethylbicyclo[4.1.0]hepta-3-ene

1-metil-7-metiliden-4-izopropiliden bisiklo[4.4.0]dekan

2,6,6-trimethylbicyclo[3.1.1]hepta-2-ene

91.cdx

1

3

4

7

8

7-methyl-3-methyleneocta-1,6-

diene

3

4

7

8

CH

2

OH

1

4

6