phg 222 (volatile oil)

8/3/2019 PHG 222 (Volatile Oil)

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VOLATILE OILS• Volatile or essential oils are volatile in steam.

• They differ entirely in both chemical andphysical properties from fixed oils.

• They are secreted in:oil cells e.g. CinnamonOil glands e.g. CloveSecretion ducts (vittae) e.g. AniseGlandular hairs e. g. Chamomile

• They are frequently associated with othersubstances such as gums ( oleo gum) andresins (oleoresin) or both (oleo gum resin)

• They tend to resinify on exposure to air.



Production and Uses of Volatile OilsThere are about 100 commercially valuable volatile

oils directly derived from plants.

• Volatile oils are used:

1- For their therapeutic action: antiseptic e.g.

thyme and clove, carminative e.g. Mentha2- Flavoring (e.g. oil of lemon),

3- in perfumery (e.g. oil of rose)

4- starting materials for the synthesis of other

compounds (e.g. oil of turpentine).



• For therapeutic purposes they are administered

as inhalations (e.g. eucalyptus oil), orally (e.g.peppermint oil), as gargles and mouthwashes(e.g. thymol) and transdermally (many essentialoils including those of lavender, rosemary andbergamot are employed in the practice of

aromatherapy).

• Those oils with a high phenol content, e.g. cloveand thyme have antiseptic properties, whereas

others are used as carminatives. Oils showingantispasmodic activity, and much used inpopular medicine. e.g. fennel, mentha, caraway,chamomile, anise, rosemary.



Composition of Volatile Oils

• Volatile oils are generally mixtures ofhydrocarbons and oxygenatedcompounds derived from thesehydrocarbons.

• The odour and taste of volatile oils ismainly determined by these oxygenated

constituents, which are to some extentsoluble in water but more soluble inalcohol.



• Practically all volatile oils consist of chemicalmixtures that are often quite complex; they vary

widely in chemical composition.

• Almost any type of organic compound may befound in volatile oils (hydrocarbons, alcohols,ketones, aldehydes, ethers, oxides, esters, and

others). “usually volatile oils are classifiedaccording to the type of organic compounds”.

• It is not uncommon for a volatile oil to containover 200 components, and often the trace

constituents are essential to the odor and flavor.The absence of even one component maychange the aroma.



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Physical PropertiesAlthough volatile oils differ greatly in their chemical

constitution, they have a number of physical

properties in common:1. They possess characteristic odors.

2. They are characterized by high refractive indices.

3. Most of them are optically active.

4. Their density is generally lower than that of water (theessential oils of sassafras, clove, or cinnamon are the

exceptions).

5. As a rule, volatile oils are immiscible with water, butthey are sufficiently soluble to impart their odor towater. The aromatic waters are dependent on this

slight solubility.



Difference between Volatile andFixed Oils

• Several points of differentiation exist betweenvolatile oils and fixed oils.

1. Volatile oils can be distilled from their natural

sources.2. Volatile oils do not consist of glyceryl esters of

fatty acids. Hence, they do not leave apermanent grease spot on paper and cannot besaponified with alkalies.

3. Volatile oils do not become rancid as do thefixed oils, but instead, on exposure to light andair, they oxidize and resinify.



Preparation of volatile oils

• The principal methods used in the preparation ofvolatile oils from plants depend on:

1. Distillation in water or steam.

2. Scarification and expression.3. Extraction with solvents.

4. Enzymatic hydrolysis (for glycosidic volatile oilse.g. mustard oil).

5. Enfleurage (extraction of oils used in perfumery).



Uses of drugs containing essential oils

• Pharmacy

• Perfumery

• Food technology

• Miscellaneous industries (as starting

materials for the synthesis of the active

principles of medicines, vitamins, and fragrances).



1- Clove (Caryophylli)

Origin: the dried flower buds ofSyzygium aromatica , Eugenia aromaticum or Eugenia caryophyllus F. Myrtaceae

Morphology: reddish brown, 16-21

mm long, the lower stalk likeportion (hypanthiumwhich is an extension of thereceptacle) is about 10-13 mmlong, terminating in 4 triangularsepals and a dome- shaped

head of 4 unexpanded petalsenclosing other parts of theflower.



Powder: dark brown, with strongaromatic spicy agreeableodour and warm spicyagreeable taste followed bynumbness sensation in themouth

1. Epidermal cells of sepals,petals and hypanthiumshowing anomocyticstomata.

2. Oil glands.

3. Parenchyma with clustercrystals of calcium oxalate.

4. Aerenchyma.

5. Xylem vessels and fibres.

6. Fibrous layer of anther andelongated cells of thefilament.

7. Pollen grains: triangular with

truncate apices.8. Absence of prisms of calcium



Active constituents:

1. Volatile oil (15 -20%) contains eugenol (85%).

2. Pyrogallol tannin.

Uses:

1. Local anesthetic for toothache.

2. Antispasmodic and carminative.3. Spice.

4. In manufacture of vanillin.

Chemical test: 1- sudan III → red colour. 2- FeCl3 → blue colour.

3- KOH: needle crystals of K eugenate.



Adulteration of clove: 1. Expanded flower

2. Mother clove (fruit): characterized by

the presence of starch.3. Exhausted clove: lighter than water.

4. Clove stalk: presence of prisms of

calcium oxalate and pseudo crystalsheath.



2- German chamomile Origin: the dried expanded

flower heads of Matricaria chamomilla F. Compositae(Asteraceae).

Morphology: flower head(capitulum) is hemispherical

with hollow receptaclecarrying two types of smallsessile flowers called florets:

Marginal or ray florets (white incolour)

Central or disc florets (yellow incolour)

Surrounded by an involucre.



Active constituents: 1- volatile oil containsmatricarin which converted to chamazuleneby heating.

2- flavonoid glycosides.

Uses: 1- carminative, antispasmodic.

2- tranquilizer.

3- local anti-inflammatory for sun burns and

diaper rashes.

Chemical test: sudan III : red colour



3- Anise Fruit(Fructus Anisi, Aniseed)

Origin: the dried ripe fruits ofPimpinella Anisum F.Umbelliferae

Morphology: cremocarp,

partly separated into itsmericarps, often entireattached to a slenderpedicel, 2-12 mm long,ovoid, enlarged at thebase and tapering at the

apex, grayish or greenishgrey in colour rough totouch due to the presenceof hairs, each mericarpwith 5 raised ridges.



Powder: grey, greenishbrown or yellowishbrown, having strong

aromatic agreeablecharacteristic taste andsweet strongly aromatictaste, showing fragmentsof:

1. non-glandular,unicellular warty hairs.2. Branching vitta usually

crossed by the cells ofthe endocarp.

3. Aleurone grains.4. Microrosette crystals of

calcium oxalate.5. Few fibres and pitted

parenchyma.



Active constituents: 1- volatile oil

containing anethol

2- fixed oil and protein.

Uses: stimulant, carminative andflavoring agent.

Chemical test: Sudan III



4- Cinnamon Bark

(Cortex Cinnamomi) Origin: the dried bark of the

branches of the coppicedtrees of Cinnamomum zylanicum F. Lauraceae.

deprived of most of itscork and cortex andknown as CeylonCinnamon.

Morphology: occurs inlong, slender sticks about1 meter in length,compound quills.



Powder: a reddish brownpowder with acharacteristic pleasant andaromatic odour and taste,showing fragments of:

1. Sclereids, isodiametric,thick wall, lignified, theouter wall is less thickenedthan the others.

2. Fibres, thick walledlignified, narrow lumen, slit-shaped pits and pointedapices.

3. Starch granules andneedle crystals of calciumoxalate.

4. Oil cells.

5. Cork cells are rare.



Active constituents: 0.5-1% volatile oil

contains cinnamaldehyde and eugenolMucilage and tannins.

Uses: 1- carminative and flavoring agents

2- Antiseptic and mild astringent.

3- Emmenagogue.

Chemical test: Sudan III, Rhuthenium red,FeCl3 and KOH for eugenol.



5- Cassia Bark(Chinese Cinnamon)

Origin: the dried stembark of Cinnamomum cassia F. Lauraceae

Morphology: channeledor single quills, up to 40cm long, earthy browncolour with patches of

the thin grayish cork.



Powder: differs thancinnamon in:

1. Odour is less delicate,taste as cinnamon butslightly mucilaginous.

2. Numerous fragmentsof cork cells, polygonalwith slightly thick wall,contains reddish

brown content.

3. Fibres are shorter andthicker.



Active constituents: volatile oilcontains cinnamaldehyde and noeugenol.

Uses: substitute for cinnamon.

Chemical test: all as cinnamon butnegative test for eugenol



6- Cardamom Seed

(Semen Cardamomi) اهيل-حب اهل-حهن Origin: the dried ripe or nearly ripe

seeds of Elettaria cardamomum F. Zingiberaceae, recentlyseparated from the fruit.

Morphology: cardamom has astrong aromatic odour andagreeable aromatic pungenttaste. Fruit is ovoid or oblongcapsule, green to pale buff incolour contains many seeds.

Seed is oblong, ovoid pale orngeto dark reddish brown usuallyenveloped by a thin colourlessmembranous arillus.



Active constituents: 1- volatile oil contains terpinylacetate and cineole.

2- starch, fixed oil and calcium oxalate

Uses: 1- flavoring agent in pharmaceutical industry.

2- spice

Chemical test: Sudan III

Adulterants:

1. Loose seeds: they yield less volatile oil than thosewhich stored in the pericarp until required for use.

2. Cardamom husk: characterized by the presenceof fibres, sclereids and large vessels which areabsent in the seeds.



7- Mentha Herb (Peppermint)(Herba Mentha Piperitae)

Origin: the dried leavesand flowering tops of

Mentha piperita F.Labiatae



Powder: green to light olive green, withan aromatic characteristic odourand an aromatic taste followed by asensation of cold in the mouth. It ischaracterized microscopically by

the presence of fragments of:

1. Epidermal cells with wavy wallsand diacytic stomata.

2. Non-glandular hairs.

3. Glandular labiaceous hair,unicellular stalk multicellular headconsists of 8-16 cells radiating froma common center.

4. Different types of xylem vessels,fibres and wood parenchyma.

5. Smooth spherical pollen grains.

6. NO CALCIUM OXALATE.



8- Ginger, Zingiber, Zanjabeel(Rhizoma Zingiberis)

Origin: the dried rhizome ofZingiber officinale F.Zingiberaceae, deprived ofthe dark outer tissues andknown as unbleachedJamaica ginger.

Morphology: ginger occurs inhorizontal laterally flattenedbranching pieces, 4-16 cmlong,1.5-6.5 cm wide andup to 2 cm thick, pale buff

or light brown, longitudinallystriated. It has anagreeable aromatic odourand an agreeable pungentaromatic taste.

P d d d i i



Powder: powdered ginger isyellowish white having anagreeable aromatic odour and anagreeable aromatic pungenttaste. Microscopically, it is

characterized by the presence of:1. thin walled parenchymacontaining starch granules.

2. Starch granules: simple, flat, oval,oblong with terminal

protruberance in which eccentrichilum is situated with transversestriations.

3. Thin walled septate fibres.

4. Non-lignified xylem vessels.

5. Yellowish brown oleo-resinmasses, free or in cells.

6. Absence of scleried cells orcalcium oxalate.



Active constituents: 1. volatile oil contains monoterpenes

(phellandrene, camphene, cineole, citraland borneol) and sesquiterpenes(zingiberene and bisabolene).

2. Resin, starch and mucilage.

Uses: 1. carminative and stimulant.2. Antiemetic.

3. Antirheumatic.4. Condiment.

phg 222 (volatile oil)

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