Terpenes & Terpenoids

1. Terpenes&Terpenoids

2. Terpenes - class of >20,000 compounds containing carbon atoms in multiples of five • Terpenoids - oxygen-containing terpenes (alcohols, ketones, aldehydes

3. 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.  rose oil (zencefil) (kereviz)

5. CH3 H2C CH CH2 C Terpenes • Terpenes are natural products that are structurally related to isoprene. or Isoprene(2-methyl-1,3-butadiene)

6. CH3 CH2 CH2 CHCH2CH2CCH CH3C Terpenes • Myrcene (isolated from oil of bayberry) is a typical terpene. or

7. The Isoprene Unit • An isoprene unit is the carbon skeleton of isoprene (ignoring the double bonds) Myrcene contains two isoprene units.

8. The Isoprene Unit • The isoprene units of myrcene are joined "head-to-tail." head tail tail head

9. Classification of Terpenes • Class Number of carbon atoms • Monoterpene 10 • Sesquiterpene 15 • Diterpene 20 • Sesterpene 25 • Triterpene 30 • Tetraterpene 40

10. OH O H Representative Monoterpenes a-Phellandrene(eucalyptus) Menthol(peppermint) Citral(lemon grass)

11. OH O H Representative Monoterpenes a-Phellandrene(eucalyptus) Menthol(peppermint) Citral(lemon grass)

12. Representative Monoterpenes a-Phellandrene(eucalyptus) Menthol(peppermint) Citral(lemon grass)

13. Representative Sesquiterpenes H a-Selinene(celery)

14. Representative Sesquiterpenes H a-Selinene(celery)

15. Representative Sesquiterpenes a-Selinene(celery)

16. OH Representative Diterpenes Vitamin A

17. OH Representative Diterpenes Vitamin A

18. Representative Diterpenes Vitamin A

19. Representative Triterpene tail-to-tail linkage of isoprene units Squalene(shark liver oil)

20. Finding the isoprene building block - cyclic compounds Finding the isoprene building block - sesquiterpenes (C15)

21. 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

22. Finding the isoprene building block - tetraterpenes (C40) • Lycopene is responsible for the red color in tomatoes and watermelon

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

24. ” C10 terpenoids • The precursor to C10 terpenoids (monoterpenes) is Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), which consists of two C5 “isoprene units” that are joined “head-to-tail • PP head - tail head - tail

25. Geranyl pyrophosphate

26. C15sesquiterpenoids • are derived from Farnesyl diphosphate, • which consists of three C5 “isoprene units” that are joined • “head-to-tail”

28. C20diterpenoids • are derived from Geranylgeranyl diphosphate, • which consists of four C5 “isoprene units” that are joined • “head-to-tail”

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

30. Examples of the co-existence of systematics Semi-systemetic and trivial names

31. Menthol – a cyclic terpenoid This terpene has been oxidised to a terpenoid

32. Absinthe – a cyclic terpenoid a potent green aniseed-flavoured liqueur, originally made with the shrub wormwood.(the seed of the anise, used in cooking and herbal medicine) This terpene has been oxidised to a terpenoid

33. Camphor – a cyclic terpenoid

34. a-Selinene – a cyclic terpene 3 isoprene units 15 carbon atoms

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

36. Questions • Which unit makes up every terpene? Isoprene Unit • How many carbons are there 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

37. Carvone • Occurs in Enantiomeric forms • Also known as Meridian fennel, Persian carrot • Uses • Carvone –Latin name for Caraway, carumcarvi • Basic carbon skeleton • 1-isopropyl-4-methylcyclohexane common in nature the genus menthaincludes various types of mint

38. saturated ketone of the p- menthane family of monoteroenoids • Greek letters • Use to distinguish between isomeric terpenoids • Depends on • In order in which the isomers were discovered • Their abundance

39. α- Pinene¾ component of turpentine oil by weight • β- Pinene next most significant component

40. Cyclic Terpenoids • α, β, andγrefers to the location of double bond in isomeric olefins • α - endocyclic tri substituted double bond • β- A tetra substituted olefinic bond • γ- exocyclic methylene function • Example E1 reaction

42. α - endocyclic tri substituted double bond • A trisubstituted alkene is an alkene in the molecule of which the doubly bonded carbons are bonded to a total of three carbon atoms excluding each other.

43. A tetrasubstituted alkene is an alkene in the molecule of which the doubly bonded carbons are bonded to a total of four carbon atoms excluding each other.

44. Methylene groupγ- exocyclic methylene function

45. 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.

46. The roles which the terpenoids play in living organisms can be grouped into three classes: • Functional • Defense and (producing resins and gums Acacia gummiferae) • Communication.

47. Examples • Vitamin A, or retinol, is the precursor for the pigment in eyes which detects light and is therefore responsible for the sense of sight. • Vitamin E, or tocopherol, is an important antioxidant which prevents oxidative damage to cells.

48. Vitamin D2, also known as calciferol, regulates calcium metabolism in the body and is therefore vital for the building and maintenance of bone. • Chlorophyll-a is a green pigment found, for example, in plant leaves and is a key factor of photosynthesis through which atmospheric carbon dioxide is converted to glucose.

50. Calciferol