fully described definition

1. Terpenes and Terpenoids
Presented by :
Jitu Kumar Agarwal

2. What are Terpenes?
Terpenes are strong smelling natural
compounds which are produced by a
variety of plants specially conifers.

3. Occurence
• They originate from Terpentine , which flows
on cutting or curving the bark and new wood
of several pine tree species.

4. General Definition of Terpene
• Any naturally occuring compounds built up of
isporene subunits are called terpenes.
Isoprene

5. Terpenoids
Substiuted
Terpenes
are called
as
terpenoids.

6. Isoprene Rule And Special Isoprene
Rule
• These rules states that:
• The molecules of all terpenes are constituted
of two or more isoprene units.
• In Natural terpenoids isoprene units were
linked head to tail arrangement, head being
the branched end.

7. Head to tail arrangement

8. Classification
of Terpenes
• Hemiterpenes consist of a single isoprene
unit.
• Monoterpenes consist of two isoprene units
• Sesquiterpenes consist of three isoprene
units
• Diterpenes are composed of four isoprene
units
• Sesterterpenes, terpenes have five
isoprene units
• Triterpenes consist of six isoprene units.
• Sesquarterpenes are composed of seven
isoprene units.
• Tetraterpenes contain eight isoprene units.
• Polyterpenes consist of long chains of many
isoprene units.
Terpenes may be
classified according
to the number of
isoprene units
present in the
molecule.

9. General Properties
• Colorless except a few
• Pleasantly smelling
• Highly refractive solids or liquids
• Insoluble in water, volatile in steam.
• Optically active, some are reacimic
• Lighter than water
• Boiling point 150-180°C

10. Citral
Occurs in 70 to 80 % in Lemon Grass oil. It is also
found in oil of Orange, oil of lemon and in
Citronella oil.

11. Isomers of Citral
Both give same chemical
reactions
Difference is found on the rate of
cyclisation of their corresponding alcohols

12. Alpha Terpeniol

13. The End