Terpenes and Terpenoids Prof Navanath Bhausaheb Chede 2018

Terpenes and Terpenoids Prof. Navanath Bhausaheb Chede 2018 -19

The name "terpene" is derived from the word "turpentine" Terpenes and terpenoids are the primary constituents of the essential oils of many types of plants and flowers

Terpenes • Terpenes are natural products that are structurally CH related to isoprene. 3 H 2 C C CH CH 2 or Isoprene (2 -methyl-1, 3 -butadiene)

• Geraniol is found in the scent of many flowers such as the rose. • Its presence attracts insects to the flower and it can be classified as a Synomone since the attracted insect finds nectar and the plant obtains a pollinator. • It is a type of monoterpenes.

Finding the isoprene building block - cyclic compounds Finding the isoprene building block sesquiterpenes (C 15) 5

Finding the isoprene building block triterpenes (C 30) - 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 (C 40) • Lycopene is responsible for the red color in tomatoes and watermelon

-carotene is the compound that causes carrots and apricots to be orange

” C 10 terpenoids • The precursor to C 10 terpenoids (monoterpenes) is Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), which consists of two C 5 “isoprene units” that are joined “head-to-tail • • PP head - tail

C 15 sesquiterpenoids • are derived from Farnesyl diphosphate, diphosphate • which consists of three C 5 “isoprene units” that are joined • “head-to-tail”

C 20 diterpenoids • are derived from Geranylgeranyl diphosphate, • which consists of four C 5 “isoprene units” that are joined • “head-to-tail”

Terpenoid nomenclature Groups and subgroups Based on pathways Classification IUPAC CAS Trivial name(derived from the structural family • Or relate to natural source) • • •

β-carotene – a linear terpene 8 isoprene units 40 carbon atoms

THE ROLE OF TERPENOIDS IN NATURE • Terpenoids are produced by a wide variety of plants, animals and micro-organisms. • As for all metabolites, the synthesis of terpenoids places a metabolic load on the organism which produces them and so, almost invariably, there is a role which the material plays and for which it is synthesized.