terpenoid
TRANSCRIPT
TERPENOID
(ISOPRENOID)
Natural products that posses a carbon framework comprised of units of five carbon arrangement as below:
isoprenic isoprenic isoprenic isoprenic
commonly indicated by
symbol C5
Terpenes:
DEFINITION
1. Hemiterpenes (1 x C5)
3-methylbut-2-en-1-ol
HO
(γ,γ-dimethylallyl alcohol)
Prenol
Etil isovalerat
Classification of Terpenes
Based on isoprenic
Asam isovalerat
2. Monoterpenes (2 x C5)
OH
menthol geraniol
OH
limonene
(mint) (roses) (orange fruit)
Sources: volatile oil (minyak atsiri)
β-Mircena
3. Sesquiterpenes (3 x C5)
OH
farnesol bisabolen
Zingiberene
Sources: volatile oil (minyak atsiri)
β-Kurkumena
α-(-)-Bisabolol
Bunga, daun, buah dan akar dari bermacam tumbuhan mengandung bahan yang mudah menguap dan berbau wangi
Minyak atsiri terdapat pada
cengkehkayu manispinaceaepinusumbelliferae ketumbarsaladri adas
4. Diterpenes (4 x C5)
OH
manoolCOOH
pimaric acid
Sources: pine resin
Cembren
Kafestol
5. Sesterterpenes (5 x C5)
gascardic acid
COOH HO
ophiobolin F
Gascardic acid is the first sesterterpenes that was isolated in 1965 from the secretion of an insect, Gascardia madagascariensis
6. Triterpenes (6 x C5)
dammarane
HO
dammarenediol
OH
HO
OOH
malabaricol
Source: damar
7. Tetraterpenes (8 x C5)
lycopene
a-carotene
B-carotene
Source: carotenoid pigment (carrots)
β-
8. Polyterpenes (> 8 x C5) : polyisoprene
natural rubber
n
Frequently occur in nature, polyisoprene chains made up with more than 10 C5 units, bound tail to head
Source: natural rubber
Irregular Terpenoids
O
cryptone
O
2-methylhept-2-en-6-one β-phellandrene
Those with a skeleton of less than ten carbon atoms ►(Apparent and False Monoterpenes)
Those compounds are a defense substance from certain insects
Cryptone and 2-methylhept-2-en-6-one:Very likely derives from the oxidative cleavage of the C2-C3 bond of an acyclic monoterpene
OH
lavandulol
chrysanthemic acid
O
nezukone
OH
fenchol
those compounds contain ten carbon atoms but they do not follow the isoprene rule
It is more difficult to find a biogenetic explanation for the structures of above compounds
O
O
R
OO
R = H; CoriamyrtinR = OH; Tutin
O
O
HO
OO
Mellitoxin
OH
HO OH
OHHO
OHCHO CHOOH
Gossypol
Toxic sesquiterpenes
Coriaria species
seeds from cotton plants
Secara umum biosintesis terpenoid dengan terjadinya 3 reaksi dasar yaitu :1.Pembentukan isopren aktif (IPP dan DMAPP) berasal dari asam asetat melalui asam mevalonat 2.Penggabungan kepala ke ekor dari 2 unit isopren akan membentuk mono-, seskui-, di-, sester- dan poli-terpenoid3.Penggabungan ekor ke ekor dari unit C-15 atau C-20 menghasilkan triterpenoid (dan steroid) dan tetraterpen
Biosynthesis of Terpenoids
Biosynthesis of Terpenoids
(IPP) (DMAPP)
OPP OPP
H
MonoterpenesMonoterpenes
OPP
H
OPP
geranyl pyrophosphate (GPP)
Farnesyl pyrophosphate (FPP)
OPP SesquiterpenesSesquiterpenes
OPP
Hgeranyl-geranyl pyrophosphate (GGPP)
OPP DiterpenesDiterpenes
TriterpenesTriterpenes
2x
2x
TetraterpenesTetraterpenes
▪Hydrolysis
▪Cyclisation
▪Oxidation
▪Reduction
▪Isomerization
▪Dehydration
▪Decarboxylation
▪etc
Other reactions on GPP, FPP and GGPP to produce terpenoids:
OPP
geranyl pyrophosphate (GPP)
geraniol
OH
β-Mircena
citronellal
citral
Example:
Example:
limonene
?
α-Terpeneol
Example:
bisabolen
Example:
Reactions of Terpenoids
3-methylbut-2-en-1-ol
HO
OH
menthol
geraniol
OH