Volatile oils, also known as essential oils, are aromatic oily liquids found in many plants. They provide both therapeutic benefits and commercial uses. There are several methods to obtain volatile oils, with steam distillation being the most common. Volatile oils are complex mixtures of terpenes and phenol-derived aromatic compounds. They are classified based on their chemical structure and include hydrocarbon, alcoholic, aldehyde, and phenolic volatile oils derived from many plant parts with various medicinal properties and applications.

1. VOLATILE
OIL
Prepared by Nabeela
Jabeen
MPHIL
PHARMACOGNOSY

2. TABLE OF CONTENT
■ DEFININTIONOFVOLATILE
■ SIGNIFICANCE
■ METHODOF OBTAINING
■ SOURCES
■ ACTIVE CONSTITUENTS
■ CHEMISTRY
■ CLASSIFICATION

3. INTRODUCTION
■ “Volatile oil may be define as oily liquids which are
entirely, or almost entirely, volatile without decomposition”
 Volatile oil is also called ethereal oils or essential oils
 The last term applied because volatile oils represent the “essences” or odoriferous
constituents
 Volatile oil are colourless as rule, particularly when they are fresh, but on long
standing they may be oxidize and resinify, thus darkening in colour

4. ■ Depending on the plant, volatile oils may occur in specialized secretory structure
such as
– Glandular hairs (Labiatae)
– Modified parenchyma cells (Piperaceae)
– Oil-tubes called vittae (Umbelliferae)
– Lysigenous or schizogenous passage (Pinaceae)

5. ■ They may be formed directly by the protoplasm, by the decomposition of the
resinogenous layer of the cell wall, or by the hydrolysis of certain glycosides e.g
– Whole black mustard seeds are odourless, but upon crushing the seeds and
water to it a strong odor is evolved

6. ■ Essential oils occur in many parts of plant e.g root (vetiver), bark (cinnamon),
heartwood (sandal wood), leaves (peppermint), seed (nutmeg), flower (jasmine)
■ They are freely soluble in ether and chloroform and fairly soluble in alcohol and
they are insoluble in water
■ Exposed to air and light, many of the absorb oxygen and become what the term
ozonized oils which posses oxidizing properties

7. ■ Essential oils are derived from the
terpenes and their oxygenated
compounds
■ They are made up of isoprenes units
(C5H8)

8. SIGNIFICANCE
■ Volatile oil act as insect repellent, thus prevent the destruction of the flowers and
leaves
■ Or they may serve as insect attractive, thus aiding in cross fertilization of the
flowers
■ They are used for therapeutic action, for flavouring (lemon oils), carminative
(clove), in perfumery (rose oils), or as starting materials for the synthesis of other
compound (turpentine oil)

9. ■ Used as inhalation (eucalyptus oil),
■ orally (peppermint oil),
■ gargles and mouthwash (thymol)
■ Transdermally (lavender, rosemary)
■ Antimicrobial property (tulsi)
■ Note: oral use is minimized nowadays due to the irritation which are produce to
the mucous membrane

11. Method of obtaining of volatile oil
■ There are many different ways to extract essential oils and they are listed below:
■ Enfleurage
■ Expressed Oils
■ Steam Distillation
■ Solvent Extraction
■ Fractional Distillation and Percolation
■ Carbon Dioxide Extraction
■ Phytonic Process

12. Enfleurage
■ Enfleurage is one of the oldest methods of
extracting essential oils and is rarely used these
days because of its high cost.
■ It involves placing the flower petals on a layer of
glass that is first spread with a thin layer of
fat called "chassis".
■ The volatile oil diffuses into the fat, then the fat
is collected and the oil is extracted from the fat
using alcohol.

13. ■ Once the alcohol evaporates what is left behind is called the absolute.
■ As you can imagine, this is a very time consuming process, but it was the only way
to extract delicate flowers like Jasmine for a very long time!

14. Expressed Oils
■ When oils are taken from the rind of fruits they are called "expressed oils".
■ This method is cold and does not involve any solvents or heat of any kind.
■ Most of the citrus oils are extracted in this manner including grapefruit, lime, orange
and lemon essential oils.
■ These are not technically considered essential oils for this reason, but they are still
definitely therapeutic oils.

15. ■ The most important thing to consider with cold pressed oils is the source of the
crop since citrus fruits are constantly sprayed with pesticides and it can be very
concentrated in the oil!

16. Steam Distillation
■ There are actually three different steam processes that are described further in
the distilling section.
■ But in all of the methods, steam is used to rupture the oil membranes in the plant
and release the essential oil.
■ The steam carries the essential oil to a condenser and then as it re-liquefies the
lighter essential oil floats on top.

17. ■ The water and oil is then separated and the water portion is referred to as
the hydrosol, hydrolat, or flower or floral water.
■ And the oil portion, of course, is the essential oil!
■ The essential oil distilling equipment including the condenser, separator and
cooking chambers can all have an enormous impact on the quality of the oil.

18. Steam distillation

19. Solvent Extraction
■ Solvent extraction is a method of extracting essential oils that is dominated by the
perfume industry.
■ And technically does not produce therapeutic grade oils because chemicals such as
hexane, acetone, di-methylene-chloride and others are used in the process!
■ The oil particles are released when the concrete substance is then mixed with
alcohol.

20. ■ Once it is separated out, the chemicals remain in the oil and the oil is used by the
perfume industry.
■ These are perfume or aromatherapy grade oils and are not therapeutic grade!
■ Are these the oils that are used in bath oils and gels, candles, shampoos, toothpaste,
fly spray, and air fresheners?
■ Yup, you got it!These are also the 98% of the oils sold in health food stores, retail outlets
and aromatherapy suppliers!

21. Percolation and Fractional Distillation
■ Fractional distillation separates the
volatile oil in different fractions or
portions at various boiling points.
■ This is used in oil refineries for
distillation of petroleum products and
is not suited for therapeutic grade
essential oils.

22. ■ Percolation is one of the newer methods of extraction
essential oils.
■ It is similar to normal distillation but the equipment is
literally upside down!
■ It has been used successfully in France; however
sometimes an emulsion is produced that can not be
separated out,

23. Super Critical Fluid Extraction
(Carbon Dioxide Extraction)
Super critical fluid extraction or carbon dioxide extraction is
also a fairly new solvent extraction process that uses carbon
dioxide at very high pressure.
The carbon dioxide is injected into the tank where the plant
material is contained and acts as a solvent to extract the oil.

24. ■ The carbon dioxide is colorless and odorless liquid and can be completely removed
which is a good thing; however,
■ There is no research at this point to verify if there are any effects of using this
procedure.
■ Additionally, the distilling equipment is extremely expensive.
■ So until more is known about this process, it is advised to use only steam distilled
and expressed oils!

27. HYDROCARBONVOLATILE OILS
■ CUBEB
■ TERPENTINEOIL

28. HYDROCARBONVOLATILE OILS
CUBEB ‫كبابة‬ TERPENTINE OIL ‫کا‬ ‫تاڑپین‬
‫تیل‬

29. Cubeb

31. Terpentine oil

32. ■

33. Alcoholic volatile oil
Coriander
Peppermint & Cardamom

34. Cardamom
■ Botanical origin Elettaria cardamomum
■ Family: Zingiberaceae
■ Chemical constituents: 3-6 volatile oil along the fixed oils,
■ Salt of potassium
■ Colouring principles
■ Nitrogenous mucilages
■ Acrid resin
■ Starch
■ Ligenous fiber

35. ■ The oil is colourless when fresh, but become thicker, more yellow and less aromatic
storage
■ It is soluble in alcohol and readily in four volumnes of 70 % alcohol, producing
■ Its specific gravity at 25C is 0.924-.0927

36. Uses
■ It is used as in aromatic
■ Carminative , Respiratory disorder like asthma,Cough, nausea, vomiting
■ Stimulant
■ Stomachic
■ Expectorant
■ Diaphoretic
■ Digestive appetizer
■ Flavouring

37. Coriander
■ Botanical origin Coriander sativum
■ Family Umbelliferae
■ Chemical constituents 1 % volatile oil coriandrol, borneol, p-cymene, geraniol,
limonene, alpha pinenes, petroselic acid, oleic acid, lanolin acid, umbelliferone,
scopoletine, malic and tannin acid

38. Uses
■ Aromatic carminative stimulant, antispasmodic diaphoretic, flavouring agent
■ Refrigent, tonic appetizer, diuretic, aphrodisiac and stomachic rheumatism and painful
joints
■ The infusions or decoction of dried fruit of cardamom is useful in treatment of
sorethroat, indigestion vomiting, flatulence

39. Peppermint oil
■ Botanical origin: Mentha piperita
■ Family: Labiatea
■ Chemical constituents: Menthol, Methyl acetate, isovalerate, menthone, cineol,
inactive pinene, limonene
■ Menthol are separated on cooling it to a low temperature

40. Aldehyde volatile oil
Bitter orange oil, sweet
orange peel, lemon
Cinnamon, bitter almond
oil

41. Bitter orange oil