Terpenoids are a large and diverse class of organic chemicals derived from the building block isoprene. They are the most abundant class of plant secondary metabolites, making up around 60% of known natural products and contributing to aromas and flavors. Terpenoids are classified based on the number of isoprene units and carbon atoms they contain, with the main classes being monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, and triterpenes. They play important roles in plants for functions like defense, signaling, and pigmentation, and some terpenoids are precursors for steroids and sterols in animals.

1. TOPIC
INTRODUCTIONAND CLASSIFICATION OF
TERPENOIDS
PREPARED BY
RIMSHA BAKHTAWAR RASHEED
MSC CHEMISTRY

2. WHAT ARE TERPENOIDS
• The terpenoids, also known as isoprenoids, are a large and diverse
class of naturally occurring organic chemicals derived from the 5-
carbon compound isoprene, and the isoprene polymers called
terpenes.
• While sometimes used interchangeably with "terpenes", terpenoids
contain additional functional groups, usually containing oxygen.
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3. • Terpenoids are the largest class of plant secondary metabolites,
representing about 60% of known natural products.
• Plant terpenoids are used for their aromatic qualities and play a role
in traditional herbal remedies.
• Terpenoids contribute to the scent of eucalyptus, the flavors of
cinnamon, cloves, and ginger, the yellow color in sunflowers, and the
red color in tomatoes.
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5. The steroids and sterols in animals are
biologically produced from terpenoid
precursors. Sometimes terpenoids are
added to proteins, e.g., to enhance
their attachment to the cell membrane;
this is known as isoprenylation.
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6. CLASSIFICATIONOF TERPENES
Terpenes are classified into many categories
based on the no. of carbon atoms and iso-
prene residues present in their structure:
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7. Classification Isoprene Units Carbon
monoterpenes 2 C10
sesquiterpenes 3 C15
diterpenes 4 C20
sesterterpenes 5 C25
Triterpenes 6 C30
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8. ISOPRENE RULES
• A majority of these compounds are found only in plants, but some of
the larger and more complex terpenes (e.g. squalene & lanosterol)
occur in animals.
• Terpenes may be considered to be made up of isoprene (more
accurately isopentane) units, an empirical feature known as the
isoprene rule. Because of this, terpenes usually have 5n carbon
atoms ( n is an integer), and are subdivided as follows:
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9. • Examples of C10 and higher terpenes, representing the four most
common classes are shown in the following diagrams.
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10. Monoterpenes and sesquiterpenes
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