Phamacognosy: volatileoils_Mathias SN.pptx

hytochemistry of the volatile oils: Introduction: definition and occurrence, characteristics
chemical nature, classification; Extraction of volatile oils from their natural sources, medicinal
and other uses, distinction between fixed oils and volatile oils; Detailed study of the following
volatile containing drugs including their sources, distinguishing characters, cultivation,
collection, extraction, constituents and uses. Drug examples: Peppermint, Cardamon, Clove,
Cinnamon, Campher and Eucalyptus;

1. VOLATILE OILS Prepared by- Sylvester Nefai Mathias ( Assoc. Professor) Department of Pharmarcognosy & EthnoPharmacy , UDUS P H A R M A C O G N O S Y

2. Definition Volatile oils are the odorous and volatile products of various plant; a s they have a tendency to undergo evaporation on being exposed to the air even at an ambient temperature , hence are invariably termed as volatile oils , essential oil or ethereal oils. Chemically, they are composed of hydrocarbons of the general formula (C 5 H 8 ) and their oxygenated, hydrogenated and dehydrogenated derivatives. All the volatile oils are of vegetable origin . These volatile oils are usually formed by two modes namely : by hydrolysis of some glycosides ; and, by the protoplasm directly.

3. In most instances, the volatile oil preexists in the plant and is usually contained in some special secretory tissues as glandular hairs, parenchyma cells , vittae or oil tubes , in mesophyll ( Eucalyptus leaves ), sub-epidermal tissues of Lemon and Orange . in lysigenous or schizogenous passages , in all tissues ( Conifers ), In petals ( Orange, Rose ), in bark and leaves ( Cinnamon ), in pericarp ( Umbelliferous fruits ), in glandular hairs of the stems and leaves ( Mint ), and in rind ( Orange ). These represent essence of active constituents of the plant and hence also known as essential oils. Why are they called Essential Oil?

4. They are evaporated at ordinary temperature Volatile oils are colourless liquids, but when exposed to air and direct sunlight these become darker due to oxidation . To prevent this darkening, they should he stored in a cool, dry place in tightly stoppered preferably amber glass containers . They possess characteristic odors Characterized by high refractive indices Most of them are optically active [specific rotation is often a valuable diagnostic properties] Physical Properties

5. Volatile oils are immiscible with water , but they are sufficiently soluble to impart their odor to water Soluble in ether, alcohol, chloroform and most organic solvents . Volatile oils neither leave permanent grease spot on filter paper nor saponified with alkalis They are present in entire plants (Mint , Conifers) or any part of the plant (Rose)

6. No Volatile oil Fixed oil 1. Volatile oil can evaporate when placed under room temperature Fixed oils do not evaporate at room temperature   2. Mixtures of cleoptenes & stearoptenes are termed as volatile oils Esters of higher fatty acids & glycerin are known as fixed oils.   3 Their primary source is leaves, roots, in petals and bark . Their major source is seeds of the plant and animal.   4. Possess high refractive index Possess low refractive index   5. These are optically active . These are optically inactive .   6. There is no spot (no permanent stain) left after evaporation Some type of spot (permanent stain) left after evaporation   7. They are unable to undergo saponification Fixed oils can be easily saponified .   8. Essential oils do not go rancid , rather they oxidize and lose their therapeutic benefit Fixed oils can go rancid (stale) over time   9. Colorless Some possess colors (yellowish)   10. Have characteristic odor May or may not possess odor   11. Immiscible in water Soluble in water   12. Obtained by distillation Obtained by extraction   13. Low boiling point High boiling point   14. Soybean oil, castor oil Cinnamon oil, peppermint oil.

7. Chemical composition Many volatile oils consist largely of Terpenes . The term ‘ terpene ’ was given to the compounds isolated from terpentine , a volatile liquid isolated from pine trees. But there is a tendency to use more general term ‘ terpenoids ’, which includes hydrocarbons and their oxygenated derivatives . Terpenoids are volatile substances which give plants and flowers their fragrance ‘ Terpenoids are the hydrocarbons of plant origin of the general formula (C 5 H 8 )n as well as their oxygenated, hydrogenated, and dehydrogenated derivatives.’

8. Isoprene Rule Isoprene rule states that the terpenoid molecules are constructed from two or more isoprene unit . Special Isoprene Rule It states that the terpenoid molecules are constructed of two or more isoprene units joined in a ‘head to tail’ fashion . But this rule can only be used as guiding principle and not as a fixed rule

9. Acetate mevalonate/ mevalonic acid/ isoprenoids / methylerythritol pathway The acetate is utilized in the form of Acetly CO-A, as the active form of acetate. Recall from the Biogenesis of the Biosynthesis of TERPENOIDS

10. Mevalonate pathway plays a critical role in biosynthesis of isoprenoid derivatives Acetyl CoA is the precursor of this pathway. Mevalonic acid is the major intermediate Terpenoids and steroids can be formed through this pathway

11. Acetate mevalonate pathway is basic metabolism pathway which is useful for biosynthesis of various secondary metabolites like hemiterpenes, sesquiterpenes , carotenoids, squalene, steroids etc. The mevalonate pathway begins with acetyl-CoA and ends with production of isopentenyl pyrophosphate (IPP) and dimethyl pyrophosphate (DMAPP) which are used to make isoprenoids, a diverse class of 30,000 biomolecules such as cholerestrol , vitamin K, and all steroid hormones. The terms terpenoid and isoprenoid are interchangeable, isoprenoid referring to the five-carbon isoprene unit from which all terpenoids are theoretically derived Acetate- malonate pathway (extensions) Includes synthesis of fatty acids and aromatic compounds with the help of secondary metabolites. Main precursor of acetate- malonate pathway are acetyl-CoA and malonyl -CoA. End product of this pathway can be saturated or unsaturated fatty acids, acetyl easters , amides or polyketides . Polyketides are secondary metabolites which further synthesize aromatic compounds by polyketide pathway.

12. acyl carrier protein (ACP)

13. Most natural terpenoid hydrocarbons have the general formula (C 5 H 8 ) n . They can be classified on the basis of number of carbon atoms present in the structure . Monoterpenoids , 2 isoprene units (C 5 H 8 ) 2 Sesquiterpenoids , 3 isoprene units (C 5 H 8 ) 3 Diterpenoids , 4 isoprene units  (C 5 H 8 ) 4 Triterpenoids , 6 isoprene units (C 5 H 8 ) 6 Tetraterpenoids , 8 isoprene units  (C 5 H 8 ) 8 Polyterpenoid  with a larger number (>8) of isoprene units (C 5 H 8 ) > 8 Classification of Terpinoids

14. limonene Monoterpenes Sesquiterpenes Triterpenes Lanosterol Polyterpene Cinnamaldehyde

15. Each class can be further subdivided into subclasses according to the number of rings present in the structure . 1. Acyclic Terpenoids : They contain open structure. 2. Monocyclic Terpenoids : They contain one ring in the structure . 3. Bicyclic Terpenoids : They contain two rings in the structure . 4. Tricyclic Terpenoids : They contain three rings in the structure . 5. Tetracyclic Terpenoids : They contain four rings in the structure .

16. Acyclic L imonene Monocyclic Bicyclic Tricyclic Tetracyclic Lanosterol

17. Sources of Volatile oil Dried ripe fruits: Coriandar oil , Anise oil Fresh ripe fruit: Lemon oil Dried ripe fruit rind: Bitter range oil Dried leaves and flowering tops: Peppermint oil, Spearmint oil. Fresh leaves: Eucalyptus oil Dried bark: Cinnamon oil Dried stigma and style tops: Saffron oil Dried flower buds: Clove oil Dried ripe seed: Nutmeg oil, Cardamom oil Dried peel rhizome: Calamus oil Aerial part: Chenopodium oil Dried roots rhizome: Valerian oil Ripe bulb: Garlic oil Wood : Sandal wood oil Unripe fruit: Black pepper oil.

18. On the basis of chemical composition of volatile oil- Alcohol volatile oils: Coriander oil, Cardamom oil, Rose oil Aldehyde Volatile Oils: Cinnamon oil, Lemon oil, Saffron oil Ketone Volatile oil: Camphor oil, Caraway oil, Spearmint oil Phenol volatile oil: Clove oil, Thyme oil, Phenolic ether Volatile oil: Nutmeg oil, Anise oil Oxides volatile oil: Eucalyptus oil, Chenopodium oil Ester volatile oil: Lavender oil Classification

19. Natural drugs containing volatile oils can be tested by following chemical tests : 1. Thin section of drug on treatment with alcoholic solution of Sudan III develops red color in the presence of volatile oils . 2. Thin section of drug is treated with tincture of alkana , which produces red color that indicates the presence of volatile oils in natural drugs. CHEMICAL TESTS

20. Volatile oils are used as flavouring agent, perfuming agent in pharmaceutical formulations, foods, beverages, and in cosmetic industries . These are also used as important medicinal agent for therapeutic purposes like : 1. Carminative (e.g. Umbilliferous fruits) 2. Anti- helminitic (e.g. Chenopodium oil) 3. Diuretics (e.g. Juniper) 4. Antiseptic (e.g. Eucalyptus) 5. Counter irritant (e.g. Oil of winter green) 6. Local anesthetic (e.g. Clove) 7. Sedative (e.g. Jatamansi ) 8. Insect repellent (e.g. Citronella) 10. Source of vitamin A (e.g. Lemongrass) PHARMACEUTICAL APPLICATIONS Counter irritant: An externally applied substance that causes irritation or mild inflammation of the skin for the purpose of relieving pain in muscles, joints and viscera distal to the site of application

21. PREPARATION OF VOLATILE OILS Enzymatic Hydrolysis Distillation Method Expression/ Ecuelle Method Extraction Method Destructive Distillation Water Water + Steam Steam Vacuum CO 2 Extraction Enfleurage 1 2 3 4 5

22. Volatile oils are usually obtained by distillation of the plant part containing the oil The method depends on the condition of the plant material. DISTLLATION PROCESS Steam Distillation Water & Steam Distillation Water Distillation

23. Sample: Which are not destroyed or injured by boiling up to 100 o C Dried plant sample WATER DISTILLATION

24. A small piece of dried plant material is introduced into the distilling chamber Water is added Heated up to 100 o C Vapor of volatile oil and water goes into the condenser After being condensed, volatile oil is separated by Florentine Flask PROCEDURE Florentine Flasks of the type FLW or FHW depending on whether the resulting oil is lighter than water or heavier than water.

25. The distillation flask is heated initially to start the process of steam distillation. Once the distillation commences the heat of the steam entering the flask not only maintains the high-temperature required but also in removing the volatile components to the water condenser for ultimate collection in the respective Florentine Flask. E xcess heat must be avoided Process must be air tight Full amount of the water must be vaporized. CAUTIONS

26. Sample: Fresh material Materials which may be injured by direct boiling Materials which may be hydrolyzed Example: Peppermint Oil STEAM DISTILLATION NO MECERATION

27. The plant sample taken into a metal distillation chamber over the perforated tray The steam is forced to the fresh sample from below Then the vapor of the volatile oil and steam is passed through the condenser The volatile oil is finally separated through Florentine flask   PROCEDURE

28. Samples: Both fresh and dried samples Materials which may be injured by direct boiling Example: Clove Oil, Cinnamon Oil WATER AND STEAM DISTILLATION MECERATION BEFORE STEAM DISTILLATION

29. The sample is put into a flask with water so that the sample is well mecerated Steam is generated else where to prevent the impairing of drug due to direct heat is passed through the mecerated mixture The vapor of volatile oil and liquid pass through the condenser Two layer is formed – one is oleaginous layer and another is aqueous layer Finally the volatile oil is separated through Florentine flask. PROCEDURE

30. Performed under reduced pressure This technique separates compounds based on differences in boiling points difficult to achieve or will cause the compound to decompose pressure boiling point of compounds F resh plant parts Heat sensitive materials Prevent the oxidation of volatile oils. VACUUM DISTILLATION

31. Sample with water is introduced into the distilling chamber Hg-pump is added to remove gas and create the vacuum Heat is applied and the steam of oil and water are passed through the condenser Finally the volatile oil is separated through Florentine flask PROCEDURE

32. Hg-Pump

33. There are some glycosides which contain volatile oil. To separate these types of volatile oils, we need Enzymatic Hydrolysis process. ENZYMATIC HYDROLYSIS

34. Amygdalase , Prunase Myrosine C 6 H 11 O 5 1. 2.

35. 3 .

36. Often referred to as “cold pressing.” The term expression refers to any physical process in which the essential oil glands in the peel are crushed or broken to release the oil. Sample: citrus essential oils, such as tangerine, lemon, bergamot, sweet orange, and lime, This method involves the rind portion of the fruit, or the outermost waxy layer of the fruit’s peel This method is most useful with plant materials that lose their fragrance and beneficial properties when exposed to the temperatures required for steam distillation Oil is forced from the material under high mechanical pressure and generally produces a good quality oil EXPRESSION

37. SPONGE EXTRACTION PROCESS

38. The whole of the above process is carried out in cool, darkened rooms to minimize the harmful effects of heat and light on the oil

39. In this process, the rinds are ruptured mechanically using numerous pointed projections with a rotary movement and the oil is collected. Ecuelle a piquer is a specially designed apparatus is nothing but a large bowl meant for pricking the outer surface of citrus fruits. It is more or less a large funnel made of copper having its inner layer tinned properly. The inner layer has numerous pointed metal needles just long enough to penetrate the epidermis. The lower stem of the apparatus serve two purposes; first, as a receiver for the oil; and secondly, as a handle . ECUELLE EXTRACTION PROCESS

40. PROCESS

41. Or

42. The plant material containing the volatile oil is usually extracted with a low boiling volatile solvent , such as n-hexane, benzene, petroleum ether etc ., either by adopting the method of hot continuous extraction ( Soxhlet extraction) or by percolation Process depends on the nature of volatile oil Extraction Method

43. Carbondioxide Extraction

44. Enfleurage method

45. Destructive distillation Destructive distillation is the chemical process of the decomposition of unprocessed material by heating it to a high temperature Empyreumatic oils : being or having an odor of burnt organic matter as a result of decomposition at high temperatures  Destructive distillation is a means of obtaining Empyreumatic oils

46. Plants containing volatile oils

47. Obtained from the dried flower buds of Syzygium aromaticum ( Eugenia caryophyllus ) Family : Myrtaceae Obtained by Steam distillation process. Clove oil Physical properties: Colorless or pale yellow liquid Spicy order and pungent taste It becomes darker and thicker on exposure to air and by aging.

48. Clove oil Eugenol (70-95%) Eugenol acetate (3%) ß- caryophyllene Methyl amyl ketone Methyl furfural Carbinol Vanillin Methyl-n- heptyl -ketone Methyl salicylate Methyl benzoate Methyl alcohol Benzyl alcohol Furfuryl alcohol Furfural Methyl furfuryl alcohol 2-heptanol 2 nonalol Trace amount

49. Chemical structure Methyl benzoate Furfural alcohol 2-heptanol

50. Flavoring agent Commercially producing vanillin Antioxidant In throat infection Remove fatigue Toothache remedy Antiseptic Counterirritant Carminative Mouthwash Dental preperation ( eugenol ) Antimicrobial (diarrhea, intestinal worms, and other digestive ailments) Eugenol is also used as local anaesthetic in small doses. The oil stimulates peristalsis; it is a strong germicide, also a stimulating expectorant in bronchial problems. Antiemetic Uses 85% volatile oil Phenolic type Eugenol

51. Cinnamon oil Obtained from the leaves and barks of Cinnamonum cassia Family : Lauraceae Obtained by Steam distillation process. Also known as cassia oil Physical properties: Yellowish or brownish color Sweet in taste Spicy delicate fragrance.

52. Chemical constituents Cinnamaldehyde (80-95%) Cinnamyl acetate Limonene Linalool Eugenol (4-10%) Mannitol (sweet taste) ß- Caryophyllene p-cymene Cinnamon oil

53. Chemical structure limonene Cinnamaldehyde Cinnamalacetate

54. Uses Mild antiseptic Carminative Astringent Flavoring agent Anti- diarrhoeal Increase the action of insulin

55. Source : Peppermint consists of dried leaves and flowering tops of Mentha pipenta Family : Labiatae . Distilled with steam from the fresh overground parts Peppermint oil Physical properties: Colourless , pale yellow or greenish yellow liquid Strong agreeable odour and a powerful aromatic taste, followed by a cooling sensation when air is drawn into the mouth

56. Peppermint Oil Menthol (50-90%) L-and d- menthone (10%) Menthyl acetate, Menthyl valerate , Menthofuran , Jasmone , Phellandrene . Pinene . Cineole, Limonene, Terpinene , Cadinene , Amyl alcohol, Acetic acid, isovaleric acid. Acetaldehyde, isovalenc aldehyde Piperitone

57. Chemical structure Menthol Menthone Menthylacetate Eucalyptol/ cineol Piperitone

58. Uses Flavoring agent Carminative Stimulant Counterirritant Reducing gastralgia , nausea , flatulence and vomiting Mild antiseptic and local anaesthetic properties Externally in rheumatism, neuralgia, headache and toothache. Peppermint oil is used for flavoring in pharmaceuticals. dental preparation, mouth washes, cough, drops, soaps, chewing gums, candles, confectionery and alcoholic liquers chewing gum 55%; toothpaste, mouthwash, and pharmaceuticals 34%; confectionary products, 10%; and other products 1 %.

59. Sources : dried, scythe-shaped the fresh leaves of various species of Eucalyptus such as E. globulus Labill . E. polybractea . E . smithii , E. vimino.lis , and E. australlana . Family : Myrtaceae Obtained by Steam distillation. Physical properties: The oil is a colorless or pale yellow liquid that has a characteristic, aromatic, camphoraceous odor and a pungent, spicy, cooling taste Eucalyptus oil

60. Eucalyptus oil Cineol/eucalyptol (70-85%) P- coumaric acid Terpenes Rutin Dihydroflavinol P-cymene, α- pinene Gallic acid Eucalyptin Eucalyptic acid Resin Tannic acid Camphene, Butyric aldehyde, valerenic aldehyde, caproic aldehyde, aromadendrene , cuminaldehyde , Pinocarveol , and phellandrene

61. Chemical structure Eucalyptol/ cineol P- coumaric acid Dihydro flavinol P-cymene α phellandrene cuminaldehyde Gallic acid

62. Uses Stimulant, Antiseptic, Flavoring agent, Aroma therapy, Deodorant, Expectorant, Antimicrobial, Febrifuge, Diuretic, Antispasmodic. Used in the treatment of lung diseases, sore throat, cold A vapour bath for asthma and various respiratory ailments and in bronchitis Burns and as mosquito repellant . Eucalyptus Increases the flow of saliva , gastric and intestinal juices and thus increases appetite and digestion. It increases the rate of heart beats, lowers the arterial tension and quickens respiration . Toxic doses it is a narcotic poison. It paralyses the respiratory center in the medulla It is taken internally in the form of mixtures, inhalations, lozenges and pastilles and applied externally as ointments and liniments.

63. The star-anise oil is obtained from Illicium verum Family : Illiciaceae Chemical constituents: Anise seed oil Anise seed oil Anethole (87–94%) Estragole (0.5–5.0%) Anisaldehyde (0.1–0.5%) Foeniculin (0.1–3.0%); Anisic acid, Anise ketone, Β- caryophylline , Linalool; Polymers of anethole , dianethole , and photoanethole . Coumarins Flavonoid glycosides ( rutin , isovitexin and quercetin ), Phenylpropanoids .

64. Uses Flavouring agents Carminatives Expectorant Used in the treatment of bronchitis, asthma, Antimicrobial Antispasmodic. Enhance the memory, Increases lactation, Relieves menopausal discomforts, Whooping cough, Externally in scabies, Overcomes nausea, and as a digestive .

65. Nutmeg is the kernel of the dried ripe seed of Myristica fragrans Family : Myristicaceae . Obtained from distilled with steam The oil is a colorless or pale yellow liquid that has the characteristic odor and taste of nutmeg . Nutmeg oil

66. Nutmeg oil α- pinene (15–26%), β- pinene (13–18%), sabinine (14–29%), myristicin (5–12%), limonene (2–7%), γ- terpinene (2–6%), terpinen-4-ol (2–6%), car-3-ene (0.5–2%), safrole (2.5% maximum). Elemicin and isoelemicin , Eugenol , Methyleugenol Methoxyeugenol Methylisoeugeol Isoeugenol . Clemicine , Geraniol , Borneol , Camphene, Dipentene . Myristic acid Major Minor

67. γ

68. Flavoring agent Carminative, Astringent, Aphrodisiac, Stomachic Nausea and vomiting Antibacterial activity. Ingestion of large quantities causes drowsiness, stupor and death. It has narcotic action and peripherally it irritates and produces anesthetics action, since it irritates intestine and uterus it can cause abortion. Uses

69. Biological Source : Fennel oil is obtained from the dried, ripe fruits of F'oeniculum vulgare . Family : Umbelliferae Chemical constituents: Fennel seed oil Anethole (55–75%) Fenchone (12–25%) Anisaldehyde (maximum 2.0%) Anisic acid, Estragole (methyl chavicol ) (maximum 5.0%). Dipentene , Limonene Phelandrene Β- pinene , Fennel

70. Stomachic Aromatic stimulant Diuretic Carminative Diaphoretic Digestive Flavouring agent Anethole may have estrogen-like activity and inhibit spasms in smooth muscles. Fennel can increase production of bile, Used in the treatment of infant colic, Reduce pain in dysmenorrhea, Can increase lactation, Act as antipyretic, Emmenagogue Antimicrobial and anti-inflammatory Anethole is used in mouth and dental preparations. Fennel is useful in diseases of the chest, spleen and kidney. Uses

71. linalool (65-70%) pinene . geranlol , boineol . p-cymene, dipentene , phellandrene , terpinolene , hydrocarbons such 3-terpinne, geraniol , n- decylic aldehyde camphor , malic acid, esters of acetic and decylic acids, tannins, and mucilage are also present. Other constituents isolated from the fruits include flavonoids, coumarins , isocoumarins , phthalides and phenolic acids. Coriander oil # Obtained from the dried, nearly ripe fruit of Coriandrum sativum Family : Umbelliferae

72. P-cymene α phellandrene

73. Uses Flavouring agent Carminative. Aromatic stimulant, Antispasmodic, Diaphoretic Appetizer, Diuretic, Aphrodisiac, Stomachic. Antibiliou Coriander oil can be applied externally for rheumatism and painful joints. The infusion of decoction of dried fruit of cardamom is useful for the treatment of sore-throat, indigestion, vomiting, flatulence, and other intestinal disorders.

74. Study other Drug examples in similar patterns …especially, new candidate(s) volatile oil plant source(s) can be researched for your final year project work.