Alkaloids and Terpenoid’s are Secondary metabolites
Primary Metabolite Secondary Metabolites
1) Primary metabolites are essential for life These are non-essential. process. (Growth of the cells)
2)These are identified universally, throughout the source.
These are seldom, like in some portions of the source, like steam, bark, etc.
3) These are produced continuously during the growth phase and are involved in primary metabolic processes such as respiration and photosynthesis, etc
These compounds do not have a continuous production. However they are produced during non-growth phase of cells. (Synthetically).
4) Heavy mol.wt compounds.
Low mol.wt compounds.
5) Structure cannot be drawn.(Undefined)
Can be drawn. (Defined)
6) DNA, Proteins, carbohydrates, and lipids are the main primary metabolites.
Alkaloids, Terpenoid, phenolics, sterols, steroids, essential oils and lignins, etc
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Natural organic compounds.
Components of a variety of fruit and floral flavors and aromas.
Used in perfumes, essential oils and medicines.
Terpenes are unsaturated compounds formed by joining together isoprene units.
What are Terpenes?
The name "terpene" is derived from the word "turpentine"
Terpenoids - oxygen-containing terpenes (alcohols, ketones, aldehydes)
rose oil
The basic molecular formulae of terpenes are multiples of that, (C5H8)n where n is the number of linked isoprene -Isoprene - 2-methyl-1,3-butadiene- units. This is called the isoprene rule or the C5 rule.
Compounds containing carbon atoms in multiples of 5 suggest a C5 building block - isoprene units linked in a “head-to-tail” fashion.
Biogenesis or Biosynthesis of Terpenes :-
from acet:yl-coenzynte A -the biological building blockr-------..
- Acyl substitution occurs
Acctyt -CoA
Acyl halide
Biosynthesis starts from Pyruvic acid.
Pyruvic acid
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
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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
“Head” - branched end of isoprene
“Tail” - unbranched end of isoprene
Finding the isoprene building block - cyclic compounds
2-methyl-1,3-butadiene
Finding the isoprene building block - sesquiterpenes (C15)
Finding the isoprene building block - triterpenes (C30) -
Squalene has a natural and vital part in the synthesis of all plant and animal sterols, including cholesterol, steroid hormones, and vitamin D in the human body
Finding the isoprene building block - tetraterpenes (C40)
Lycopene's eleven conjugated double bonds give it its deep red color and are responsible for its antioxidant activity.
Lycopene is responsible for the red color in tomatoes and watermelon
β-carotene is the compound that causes carrots and apricots to be orange
Question : Which Terpene ?
A) Mono 2) Di 3) Sesqui 4) Sester
Humulene
found in the essential oils of Humulus lupulus
Limonene
(skin of citrus fru its)
Menthol
(peppermint)
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H3C '/CH3
c
Camphor (Camphor tree)
3 isoprene units
15 carbon atoms
a-Selinene
Pinene, terpe---, L-menthol, camphor, amyrene, geraniol, myrcene, Nerol, Carvone, Lanosterol, Cholesterol, farnesol, Artimesnin,
THC (teteahydrocannabinol), Vitamin A & D derivatives, etc
Question: Biosynthetic pathway of Cholesterol (Steroid)?
•Shikimic acid pathway
•Mevalonic acid pathway
•Acetate-melanoate pathway
•None
NOTE: All steroid moiety contain natural products are bio- synthesied by Mevalonic acid pathway
Please Check for the key words below and add ‘’Terpenoids’’ as Cpd class
Questions
Answers
Which unit makes up every terpene?
Isoprene unit
How many carbons there are in an isoprene unit?
Five
What is the systematic name for isoprene?
2-methylbuta-1,3-diene
What is an oxidised terpene known as?
Terpenoid
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