terpenoids

I. Terpenoids

In plants there are usually hydrocarbons and oxygenated hydrocarbons which are terpenoid compounds. Words terpenoid compounds include a large number of plants, and the term is used to indicate that the biosynthesis of all plant compounds that come from the same compound. So, all terpenoids derived from isoprene molecules CH2 == C (CH3) == CH2 and CH ─ carbon frame built by connecting 2 or more units of this C5. Then the compounds are broken into several categories based on the number of units contained in the compound, 2 (C10), 3 (C15), 4 (C20), 6 (C30) or 8 (C40).
Terpenoids composed of several kinds of compounds, ranging from volatile oil components, namely monoterpena and sesquiterepena volatile (C10 and C15), diterpena evaporates, the triterpenoids and sterols (C30), and carotenoid pigments (C40). Each class of terpenoids are important, both in growth and metabolism as well as the ecological tumbuha. Terpenoids are isoprene units (C5H8). Terpenoids is a compound derived carbon skeleton of the six units of isoprene biosynthesis and cyclic C30 hydrocarbons derived from the skualena. This compound is a relative cyclic complex structure, mostly in the form of alcohol, aldehyde or carboxylic atom. They form colored compounds, crystalline, high melting point and is often active optic characterized generally difficult because there is no chemical reactivity.

A.  Synthesis of terpenoid

  In general, the biosynthesis of terpenoids three basic reactions, namely:

1. Formation of active isoprene derived from acetic acid via mevalonic acid.
2. Merging head and tail isoprene units to form mono-, seskui-, di-, Sester-, and poly-terpenoids.
3. The incorporation of the tail and the tail unit C-15 or C-20 produces triterpenoids and steroids.

acetic acid after being activated by coenzyme A did produce acid Claisen type condensation asetoasetat. Compounds produced by the condensation of acetyl coenzyme A did produce aldol type branched carbon chains as found in mevanolat acid. Subsequent reactions is phosphorylation, elimination of phosphoric acid and subsequent decarboxylation produces IPP to DMAPP by the enzyme berisomerisasi isomerase. IPP as active isoprene units joined to the tail with DMAPP and this merger is the first step of the polymerization of isoprene to produce terpenoids. This merger occurs because electrons attack the double bond carbon atoms of IPP to DMAPP electron deficient ison followed by removal of pyrophosphate. These attacks result in geranil pyrophosphate (GPP), which is an intermediate for all compounds monoterpenes.
Subsequent incorporation between the IPP and GPP unit, with the same mechanism as the IPP and DMAPP, produce farnesil pyrophosphate (FPP), which is an intermediate compound for all sesquiterpene compound. Compounds derived diterpene geranil geranil-pyrophosphate (GGPP) derived from the condensation between the units or IPP and GPP by the same mechanism as well.
 

When organic reactions are listed in Figure 2 explored more deeply, it turns out that the synthesis of terpenoids by a simpler organism is very nature. In terms of the theory of organic synthesis reaction is only using a few basic types of reactions. Subsequent reactions of the compounds between GPP, FPP and GGPP to produce terpenoid compounds one by one just involves some kind of secondary reactions as well. These secondary reactions are typically hydrolysis, cyclization, oxidation, reduction and spontaneous reactions that can take place easily in a neutral atmosphere and at room temperature, such as isomerization, dehydration, decarboxylation, and so on.

 

 

. From the equation above shows that the formation of monoterpenes compounds and compounds derived from the incorporation of 3.3 terpenoida allil dimethyl pyrophosphate with isopentenyl pyrophosphate.
In general, terpenoids composed of the elements C and H with the general molecular formula (C5H8) n.
Classification is usually dependent on the value of n. 

Nama	Rumus	Sumber
Monoterpen	C10H16	Minyak Atsiri
Seskuiterpen	C15H24	Minyak Atsiri
Diterpen	C20H32	Resin Pinus
Triterpen	C30H48	Saponin, Damar
Tetraterpen	C40H64	Pigmen, Karoten
Politerpen	(C5H8)n  n  8	Karet Alam

From the formula above most terpenoids containing carbon atoms whose numbers are multiples of five. Subsequent investigation showed also that most of the carbon skeleton terpenoids have built by two or more units called C5 isoprene unit. Unit C5 is so named because its carbon skeleton as compound isoprene. Wallach (1887) says that the skeletal structure of terpenoids constructed by two or more molecules of isoprene. This argument is known as the "law of isoprene".

B. Uses terpenoids
Uses of plant terpenoids, among others:
a. Fitoaleksin
    Fitoaleksin is an anti-microbial compound that dibiosintesis (created) and accumulated by plants after   infection of pathogenic microorganisms or exposure to certain chemicals and radiation with UV light.
b. Insect antifectan, repellant
c. Immune from herbifora
d. Pheromones plant hormones.
Pheromones are a type of chemical that serves to stimulate and have sex attractiveness in males and females].
Bioactivity terpenoids in roots and leaves of Jatropha gaumeri (distance). Because this plant terpenoids contained the compound and also in the leaf extracts have antibacterial and antioxidant activity. Activity is produced by the isolation and identification of the root that produces 2-epi-jatrogossidin (1). One was a rhamnofolane diterpene with antimicrobial activity, and both 15-epi-4E jatrogrossidentadione (2), a diterpene lathyrane without biological activity. In the same way, the purification of the studies that have been tested from the leaf extract may identified sitosterol and triterpene amaryn, traraxasterol. These metabolites it can be used as antioxidant activity.