VOLATILE OILS
VOLATILE OILS
All official volatile oils are
of vegetable origin.
Normally pre-exist in the
plant – stored in a
special secretory tissue
(e.g. Citrus peel oil cells
or oil ducts in
umbelliferous fruits).
EXCEPTION: Oil of bitter
almond – formed by
hydrolysis of the
glycosides.
USES OF VOLATILE OILS







Therapeutically (Oil of
Eucalyptus)
Flavouring (Oil of Lemon)
Perfumery (Oil of Rose)
Starting materials to
synthesize other compounds
(Oil of Turpentine)
Anti-septic – due to high
phenols (Oil of Thyme). Also
as a preservative (oils interfere
with bacterial respiration)
Anti-spasmodic (Ginger,
Lemon balm, Rosemary,
Peppermint, Chamomile,
Fennel, Caraway)
Aromatherapy
DEFINITION OF VOLATILE OILS
Volatile oils are products which are generally complex in
composition, consisting of the volatile principles
contained in plants, and are more or less modified
during the preparation process.
Only 2 procedures may be used to prepare official oils
i.
Steam distillation
ii.
Expression
4 Main types of volatile oils
i.
Concretes
ii.
Pomades
iii.
Resinoids
iv.
Absolutes
CONCRETES
Prepared from raw materials of
vegetable origin (bark,
flowers, leafs, roots etc.)
Extracted by HC type solvents,
rather than distillation or
expression – Becomes
necessary when the essential
oil is adversely affected by
hot water or steam (e.g.
jasmine).
Produces a more true-to-nature
fragrance.
CONCRETES
Concretes contain about
50 % wax and 50 %
essential oil
(jasmine).
Ylang ylang (concrete
volatile) contains 80
% essential oil and 20
% wax.
Advantages of
concretes: they are
more stable and
concentrated than
pure essential oils.
POMADES
True pomades are (volatile
oil) products of a process
known as enfleurage (hot
or cold).
Enfleurage is used for
obtaining aromatic
materials from flowers
containing volatile oils to
produce perfume long
after they were cut.
ENFLEURAGE: METHOD
A glass plate is covered with a
thin coating of especially
prepared and odourless fat
(called a chassis).
The freshly cut flowers are
individually laid on to the fat
which in time becomes
saturated with their essential
oils. The flowers are renewed
with fresh material.
Eventually the fragrance-saturated
fat, known as pomade, may be
treated with alcohol to extract
the oil from the fat.
RESINOIDS
Prepared from natural
resinous material (dried
material) by extraction
with a non-aqueous
solvent, e.g. Petroleum
ether or hexane.
E.g. Balsams – Peru
balsam or benzoin;
resins (amber or mastic);
Oleoresin (copaiba
balsam and turpentine);
Oleogum resins
(frankincense and myrrh)
RESINOIDS
Can be viscous liquids,
semi-solid or solid.
Usually homogeneous
mass of noncrystalline character.
Uses: in perfumery as
fixatives to prolong
the effect of a
fragrance.
ABSOLUTES
Obtained from a concrete,
pomade, or a resinoid by
alcoholic extraction.
The extraction process may
be repeated.
The ethanol solution is
cooled & filtered to
eliminate waxes.
The ethanol is then
removed by distillation.
They are usually highly
concentrated viscous
liquids.
Fx OF VOLATILE OILS
In most cases, the biological
function of the terpenoids
of essential oils remains
obscure – it is thought
that they play an
ecological role –
protection from predators
& attraction of pollinators.
LOCALIZATION
Synthesis & accumulation of essential oils are
generally associated with the presence of
specialized histological structures, often located
on or near the surface of the plant:
- Oil cells of Zingiberaceae
- Glandular trichomes of Lamiaceae
- Secretory cavities of Myrtaceae or Rutaceae
- Secretory canals of Apiaceae or Astereraceae
(Compositeae)
VOLATILE OIL COMPOSITION

Mixtures of HC’s and oxygenated
compounds derived from these HC’s.


Oil of turpentine – mainly HC’s
Oil of Clove – mainly oxygenated
compounds

EXCEPTION: Oils derived from
glycosides (e.g. bitter almond oil &
mustard oil).

Oxygenated compounds – responsible for
the odour/smell of the oil. They are slightly
water soluble – Rose water & Orange
Water; more alcohol soluble.

Most volatile oils are terpenoid. Some are
aromatic (benzene) derivatives mixed with
terpenes.

Some compounds are aromatic, but
terpenoid in origin (e.g. Thymol – Thyme)
CHEMICAL COMPOSITION
Volatile oils are divided into 2 main classes based
on their biosynthetic origin
i.
Terpene derivatives (formed via the acetate
mevalonic acid pathway)
ii.
Aromatic compounds (formed via the shikimic
acid-phenylpropanoid route)
iii.
Miscellaneous Origin
Volatile oils

different from fixed

components of plants that are



highly odiferous
generally occur as they are
secreted in oil cells in specialised structures
• ducts, cavities, glandular hairs

frequently associated with other substances
• gums, resins (resinify on exposure to air)

mainly terpenoid

some phenol ethers and phenols
 Terpenoids

based on the 5C isoprene unit

Monoterpenes
• most important, most volatile

di-, tri-, sesquiterpenes also important
• contain 2 condensed 5C units head-tail
• most formed from geranyl pyrophosphate
Monoterpene components
 Hydrocarbons
 Alcohols
 Aldehydes
Citral

all produced via the terpenoid pathway
 Ketones
 Esters
 Oxides
Sesquiterpenes (C15)
Hydrocarbons
Phenols
Phenolic
esters
Anethole
Chemical and physical properties

volatile liquids with no colour



odour
asymetric centres, isomers with optical activity


more soluble if contains –OH fatty acids
reasonably heat stable


is a means to characterise the oil
miscible in water and soluble in organic solvents


only one isomer occurs naturally
refractive index normally high


keep in amber bottles with minimum air
can be steam distilled
tend to be used as solvents for resins
Families

Economically only a few family groups are
commercially useful
[1] Labiatae
Lavender, Mentha Sp.
• large number, tend to hybridise
• oil occurs in special organs

synthesized in glandular trichomes (mint)
• burst easily releasing oil
[2] Umbelliferae
Fruits (best if ripe): anise, caraway, fennel, coriander
• found in “vittae” in the outer layer is characteristic
• steam distill to remove oils
[3] Pinaceae
Pine, juniper
• found in resin ducts in outer old xylem or bark
• released when bark removed
[4] Rutaceae
Citrus fruits
• typical ductless sacs in outer part of fruit – rind
• found at various depths before albino layer (white bitter pithy
part)
• oil is there under pressure and will burst open when ‘rasped’
• less stable, need more care
[5] Lauraceae
Cinnamon, camphor
• from region immediately below bark
Method of extraction

depends where oils lies and its stability

Steam distillation


Water distillation



gentle, herb + water heated and oil distilled over
wood chips in chamber and heated until water distills over
crushed sample must be stable
Cold expression



citrus fruit oil (lemon, orange, bergamot)
rasping process breaks oil sacs in rind
pour cold water over and then separate oil and water

Enfleurage



petals (rose) placed between glass sheets covered in sheep or
pig fat
oil seeps into fat and can be extracted with methanol
Destructive distillation


produces a different product from the one started with
pine and juniper heated to exclude air over
• aqueous part - wood naphtha (ethanol and crude acetic acid) to
attract juniper oil
• non-aqueous part – resin (pine tar) to attract C5-C20 molecules
including monoterpenes
• like a fractional distillation

Menthol and camphor



nearly solid at room temperature
camphor
can isolate by freezing oils out
cheaper to synthesize camphor but generally extracted from
plants
Uses
as inhalations, orally, gargles, mouthwashes, trans-dermally
[1] Flavours & carminatives
Labiatae
• Mentha piperita (peppermint oil)


50-75% menthol, also contains menthone etc
used mainly in toothpastes
• Mentha spicata (spearmint oil)


50-75% L-carvone
some minor components similar to peppermint but major
components differ giving different smell and taste
• Lavendura officinalis (lavender oil)

35-45% linalyl acetate, also geraniol, limonene, cineole
• some varieties have a lower % so other compound
characteristics dominate
• growing environment will affect quality

Rutaceae
• Citrus oils

D-limonene 90%, citral 4% + esters, pinene, d-limonene (small
amount)
• high proportion of limonene desirable
• but a lot is removed after isolation by distillation under
reduced pressure
• leaves oil high in citral which deteriorates on storage giving
a turpentine odour
• Citrus flower oils



no citral, other constituents that give a different odour and
flavour of orange flower oil
used in confectionary
Umbelliferae
• Pimpinella anisum (anise), Foeniculum vulgare (fennel)


90% anethole
some fennel variaties contain fenchone giving a bitter taste
• Carum carvi (carraway)

carvone
• Coriandum sativum (coriander)

60-80% linalool
[2] Local stimulants and antiseptics
(containing phenols)
• Pinaceae


Pinus paulastrus
• destructive distillation
• phenol p-cresol
Juniperus oxycedrus
• cadenine
• Clove

Syzygium aromaticum
• eugenol 82%
• used on sore teeth to deaden pain
• Eucalyptus oil
• 1,8-cineole 70%
(sesquiterpene)
[3] Perfumes
• Rose oil

Rosa gallica, R. damescena
• trans-geraneol
• and isomer cis-nerol
• Lavender oil
• Citrus oil
[4] Insect repellant, antimating device
• Citronella oil


from grass
doesn’t work well
[5] Starting materials
• Turpentine

(for synthesis of other compounds)
A. TERPENES
Terpenes, or
terpenoids, are the
largest group of
secondary products
(metabolites).
They are all formed
from acetyl CoA or
glycolytic
intermediates.
CLASSIFICATION OF TERPENES
All terpenes are formed
from 5-C elements
Isoprene is the basic
structural element.
CLASSIFICATION OF TERPENES
Terpenes are classified by the number of 5-C atoms they
contain
10-Carbon terpenes (contain 2 C-5 units) – monoterpenes
15- Carbon terpenes (3 C-5 units) are called
sesquiterpenes.
20-carbon terpenes (4 C-5 units) are diterpenes.
Larger terpenes (30
Carbons) are called triterpenes (triterpenoids), 40
Carbons – called tetraterpenes and polyterpenoids.
TERPENOIDS
Terpenoids contain only the
most volatile terpenes
(i.e. molecular weight is
not too high)  mono
and sesquiterpenes
May occur as oxygenated
derivatives, e.g. alcohols,
aldehydes, ketones,
phenols, oxides & esters.
EXAMPLES OF TERPENES
i.
ii.
iii.
iv.
LIMONENE
MENTHOL
BORNEOL
SESQUITERPENES
i. LIMONENE
Structural classification:
Monocyclic terpene
Functional
Classification:
Unsaturated HC
Occurrence: Citrus fruit
ii. MENTHOL
Structural classification:
Monocyclic with
hydroxyl group
Functional
classification: Alcohol
Occurrence:
Peppermint
iii. BORNEOL
Functional
Classification: ////
Occurrence: Cinnamon
iv. SESQUITERPENES
(Contain 3 isoprene units)
Acyclic – E.g. Farnesol
Monocyclic – E.g. Bisobolol
Bicyclic e.g. Chamezulene
(Chamomile)
B. AROMATIC COMPOUNDS
Many are phenols are
phenol esters
E.g. Vanillin
PROPERTIES OF VOLATILE OILS


Almost entirely volatile without
decomposition.
Density: Most are less than 1g/ml.


2 are heavier – Oil of Cinnamon and
Clove oil.
Soluble in ether, chloroform &
alcohol.
 Slightly soluble in water: give it a
characteristic odour & taste.
 Leaves a temporary translucent
stain on paper which disappears
as the oil volatilizes.
 Most are colourless. Oxidize on
exposure to air and resinify 
colour becomes darker (odour
changes slightly).
 All are characteristic odours.
 Most are optically active.
PRODUCTION OF ESSENTIAL
OILS
Essential oils may be produced
i.
By steam
- Simple steam distillation
- Saturated steam distillation
- Hydrodiffusion
i.
ii.
By expression
Other Methods
Concretes & Resinoids may be produced
i.
By solvent extraction
ii.
By methods using oils & fats
iii.
By extraction by supercritical gasses
ESSENTIAL OILS:
i.STEAM DISTILLATION
a. SIMPLE STEAM DISTILLATION
Plant material is immersed directly in a still
filled with water. This is then brought to
a boil.
Heterogeneous vapours are condensed on a
cold surface.
Essential oil separates based on difference
in density and immiscibility.
b. SATURATED STEAM
Plant does not come into contact with the water 
steam is injected through the plant material
placed on perforated trays.
It is possible to operate under moderate pressure.
Advantages: Limits the alteration of the
constituents of the oil
It shortens the duration of the treatment
It conserves energy
It can also be conducted on on-line in automated
set ups.
c. HYDRODIFFUSION
Pulses of steam is sent through the plant
material at very low pressure from (top to
bottom).
ADVANTAGE: Normally produces a
product of high quality.
Saves time and energy.
ii. EXPRESSION
(E.G.OF CITRUS EPICARPS)
The rind is lacerated, and the contents of the
ruptured secretory cavities are recovered.
CLASSIC PROCESS: an abrasive action is
applied on the surface of the fruit in a flow of
water. The solid waste is eliminated, and the
essential oil separated from the aqueous phase
by centrifugation.
OTHER machines break the cavities by
depression, and collect the essential oil directly
 prevents the degradation linked to the action
of water.
EXPRESSION OF CITRUS
EPICARPS
Most facilities allow for the simultaneous or
sequential recovery of the fruit juice and of the
essential oil, by collecting the oil with a spray of
water after the abrasion (scarification – puncture
by pins) before or during the expression of the
fruit juice.
Enzymatic treatment of the residual water allows
recycling, and markedly increases the final yield
of essential oil.
Citrus oils are also obtained directly from the fruit
juices (by vacuum de-oiling)
iii. OTHER METHODS
Steam distillation by microwaves under vacuum.
In this procedure, the plant is heated selectively
by microwave radiation in a chamber inside
which the pressure is reduced sequentially.
- fresh plants require no added water.
-
-
ADVANTAGE: This method is fast, consumes
little energy and yields a product which is most
often of a higher quality than the traditional
steam distillation product.
PRODUCTION OF CONCRETES
& RESINOIDS
SOLVENT EXTRACTION
Extraction is generally preceded by a
process of: bruising the fresh, wilted or
semi-desiccated organs, chopping
herbaceous drugs, pounding roots &
rhizomes or turning wood into chips or
shavings.
The procedure is conducted in specialized
facilities e.g. Soxhlet-type extractor.
i.
SOLVENT EXTRACTION
The solvent selection is influenced by technical &
economical factors
- Selectivity (being a good solvent for the specific
constituents).
- Stability (chemical inertness)
- Boiling point should not be so high that the solvent
can be completely eliminated; nor too low, to limit losses
& control cost
- Handling safety
Solvents most used are aliphatic HC’s – petroleum ether,
hexane, propane & liquid butane.
Although benzene is a good solvent, its toxicity
increasingly limits is use.
SOLVENT EXTRACTION
At the end of the procedure, the solvent contained
in the plant material is recovered by steam
injection.
Main disadvantages of solvent extraction
- Lack of selectivity, many lipophilic substances
may end up in the concretes & render further
purification necessary.
- The toxicity of solvents  leads to the
restrictive regulations regarding their use
- Residues in the final product.
ii. METHODS USING OILS &
FATS
These procedures take advantage of the liposolubility of
the fragrant components of plants in fats.
a. “Enfleurage” – the plant material is placed in contact
with the surface of the fat. Extraction is achieved by
- Cold diffusion into the fat
- Digestion – carried out with heat, by immersing the
plant in melted fat (also known as hot enfleurage).
The final product is known as a floral pomade.
METHODS USING OILS & FATS
b. PNEUMATIC METHOD: similar in principle to
the enfleurage process.
It involves the passage of a current of hot air
through the flowers.
The air, laden with suspended (extracted) volatile
oil, is then passed through a spray of melted fat
in which the volatile oil is absorbed.
iii. EXTRACTION BY
SUPERCRITICAL GASSES
Beyond its critical point, a fluid can have the density of a
liquid & the viscosity of a gas  therefore diffuses well
through solids, resulting in a good solvent.
CO2 is the main gas used
Advantages of CO2
- It is a natural product
- chemically inert, non-flammable
- non-toxic
- easy to completely eliminate
- selective
- readily available
- Inexpensive
EXTRACTION BY
SUPERCRITICAL GASSES
DISADVANTAGE: Technical constraints
- High cost of initial investment
ADVANTAGES:
- obtain extracts which are very close in
composition to the natural product.
- It is possible to adjust the selectivity &
viscosity, etc by fine tuning the temperature &
pressure
- All result in the increase of popularity of this
type of method
EXTRACTION BY
SUPERCRITICAL GASSES
USES
Initially developed to decaffeinate coffees, prepare
hops extracts or to remove nicotine from
tobacco, the method is now used to
- Prepare spice extracts (ginger, paprika, celery)
- Specific flavours (black tea, oak wood smoke)
- Plant oils
- To produce specified types of a certain
product, e.g. thujoneless wormwood oil.
TREATMENTS OF THE OILS
Occasionally it is necessary to decolourize,
neutralize or rectify the oils obtained.
Steam jet under vacuum
Allows for the elimination of smelly or irritating
products, and to obtain a final product of
desired “profile”.
i.
Chromatrographic techniques
This permits a good separation of the essential oil
from non-volatile lipophilic compounds.
ii.
VARIABILITY FACTORS OF
ESSENTIAL OILS
i.
ii.
iii.
iv.
Occurrence of Chemotypes
Influence of the vegetative cycle
Influence of environmental factors
Influence of preparation method
i. CHEMOTYPES
Chemical breeds
commonly occur in
plants containing
volatile oils, e.g.
Thyme (Thymus
vulgaris) – has 7
different chemotypes,
each with slightly
different types &
amounts of volatile
oils.
ii. THE VEGETATIVE CYCLE
Proportions of the different
constituents of a volatile
oil may vary greatly
throughout its
development. Wide
ranges are commonly
found in fennel, carrot
and coriander (linalool is
higher in ripe fruit than
unripe fruit). Mentha
(peppermint) is also
greatly affected by the
vegetative cycle.
iii. ENVIRONMENTAL FACTORS
Temperature, humidity,
duration of daylight
(radiation), and wind
patterns all have a direct
influence on volatile oil
content, especially in those
herbs that have superficial
histological storage
structures (e.g. glandular
trichomes). When the
localization is deeper, the oil
quality is more constant.
ENVIRONMENTAL FACTORS
e.g. Peppermint: long days
& temperate nights 
higher yields of oil &
menthofuran. Cold nights
lead to an increase in
menthol.
Laurus nobilis (Bay) [volatile
oil] is greater in the
southern hemisphere
than the northern.
Citrus: higher temperatures
= higher oil content.
ENVIRONMENTAL FACTORS
Cultivation practices
also play an important
factor to the yield &
quality of the final
product.
Fertilization and the
amounts of N, P and
K have been studied
for various species.
The watering regiment
also plays an
important role.
PREPARATION METHOD
Because of the volatile nature of the
constituents of essential oils, the
composition of the product
obtained by steam distillation is
often different from the
constituents originally found in the
secretory organs of the plant.
During steam distillation, the water,
acidity and tempereature may
induce hydrolysis of the esters.
Rearrangements, isomerizations,
racemiazations, oxidations and
other reactions also occur, all of
which change the composition.
GINGER: Zingiber officinale

Definition: Ginger is the
peeled or unpeeled
rhizome of Zingiber
officinale (Zingiberaceae).

Common Names:
Jamaican ginger, Ginger
Zingiber officinalis - Ginger
GEOGRAPHICAL SOURCES
•
•
•
Jamaica
China
India Africa
HISTORY
Cultivated in India from the
earliest times. Used by
Greeks and Romans and
was a common article of
commerce in the European
Middle Ages.
CULTIVATION & PREPARATION





Grows well in subtropical
temperatures with high
rainfall.
Grown by vegetative means.
Mulching or is necessary as
the plant rapidly exhausts
minerals from the soil.
When the stems wither, the
rhizomes are ready for
collection.
Dried.
MACROSCOPICAL FEATURES







Scraped/peeled herb has little
resemblance to the fresh herb
(loss in weight & shrinkage).
Occurs in branched pieces
“hands” or “races”.
Buds
No cork
Aromatic odour & pungent
taste.
Unscraped rhizome:
resembles scraped herb –
Covered with cork (brownish
layers)
MICROSCOPICAL FEATURES
Cork cells – high starch
content
 Cork cells are absent in
the scraped drug.
 Outer zone of flattened
parenchyma & inner
zone of normal
parenchyma.
 Oil cells scattered in the
cortex.

Zingiber officinale - CONSTITUENTS

Volatile oils (1 – 2%)




Camphene
Cineole
Citral
Borneol
Gingerol – pungent component – Anti-inflammatory
 Shogaols – increases bile secretion


Sesquiterpene HC’s




Zingiberene & Zingiberol (Sesquiterpene alcohol)
Resins
Starch
Mucilage
Zingiber officinale

VARIETIES



ALLIED DRUGS



Chinese Ginger – sliced
African ginger – darker (cortex is
grey – black in colour); lacks the
odour but more pungent than
Jamaican herb.
Japanese ginger – Z. mioga
Preserved ginger – undried rhizomes
preserved by boiling in syrup.
ADULTERANTS


Spent ginger
Vegetable adulterants (detected with
microscopical examination).
USES & ACTIONS
ACTIONS
 Carminative
 Stimulant
 Anti-emetic
 Anti-bacterial & Anti-fungal
 Sesquiterpene lactones – Anti-ulcer
 Gingerol – pungent component –
Anti-inflammatory
 Shogaols– increases bile secretion
& enhanced GIT activity
USES
 Motion Sickness
 Morning Sickness
CARDAMOM FRUIT & OIL
DEFINITION: Cardamom
consists of the dried, nearly
dried ripe fruits of Elettaria
cardamomum var miniscula
(Zingiberaceae).
PARTS USED: Seeds (should
be kept in the fruit until ready
to be used – Prevents loss of
volatile oils).
(3RD most expensive spice).
Elettaria cardamomum

GEOGRAPHICAL
SOURCES




Sri Lanka
India
Guatemala
HISTORY

Traditional Indian
ceremonies
PRODUCTION, COLLECTION &
PREPARATION

Mainly obtained from
cultivated plants
(propagated by seedlings
or vegetatively
[problematic due to virus
infection]).
 Capsules on the same
plant ripen at different
times – important to
collect them before they
split.
COLLECTION & PREPARATION





Fruits are dried slowly
(outdoors or indoors).
Too rapid drying – capsules
split & shed seeds
Calyx at the apex of the stalk
and the stalk at the base may
be removed.
Fruits are graded with a sift
into ‘longs’, ‘mediums’,
‘shorts’ & ‘tiny’.
If they have been sulphur –
bleached (improved colour),
it will be aired outdoors
before packed for transport.
MACROSCOPICAL FEATURES









Plant is reed-like - > 4 m, with long leaves
growing from the rhizome.
Fruits – capsular: inferior, ovoid, 1-2 cm long.
Apex: shortly beaked & shows floral remains.
Base: rounded & shows the remain of a stalk.
Internally the capsule is 3-celled; each cell
contains x2 row of seeds.
Each seed: Slightly angular, 4mm long & 3 mm
broad.
Colour: dark red-brown (fully ripe seeds) 
paler in unripe seeds.
Strong, pleasant, aromatic odour
Pungent taste
MICROSCOPICAL FEATURES

Oil cells
 Predominant
Parenchyma
(yellow colour)
 Cells containing
silica
 Starch grains
VARIETIES & ADULTERANTS

ADULTERATION
 Powdered drug adulterated with the fruit pericarp
(powdered).

ALLIED HERBS
 Official variety – E. cardamomum var miniscula
 Other: E. cardamomum var major (more elongated &
sometimes 4 cm long with dark brown pericarps)
 Amomum aromaticum (Bengal cardamom)
 Amomum subulatum (Nepal cardamom)
 Amomum cardamomum (Java cardamom)
CHEMICAL CONSTITUENTS
– 6.2 % volatile oil
 Abundant starch (up to 50%)
 Fixed oil (1 – 10%)
 Calcium oxalate
 2.8
Elettaria: ACTIONS & USES

Flavouring agent
(curries & biscuits)

Liqueur manufacture

Small amount is used
for pharmaceutical
manufacture
(Compound Tincture of
Cardamom).
CINNAMON: Cinnamomum
zeylanicum

DEFINITION: Cinnamon
is the dried bark of
Cinnamomum
zeylanicum (Lauraceae).

GEOGRAPHICAL
SOURCES
Cultivated in Sri Lanka,
South India, Seychelles,
Madagascar, Martinique,
Cayenne, Jamaica &
Brazil.
CULTIVATION, COLLECTION &
PREPARATION
Grown from seed
Cut down when 2-3 years
old.
After 5-6 shoots grow from
the stump (18 months),
shoots are harvested,
trimmed and fermented.
Bark is removed.
Peeled bark is then
stretched over a suitable
stick
Outer cortex is removed.
PREPARATION OF Cinnamomum
Individually scraped
barks are placed
inside each other.
Compound quills are
dried on wooden
frames in the open air
without exposure to
direct sunlight.
Sorted into grades.
MACROSCOPICAL FEATURES
Normally received in shorter lengths
known as ‘cigar lengths’.
Consists of a single or double
compound quill about 6-10 mm
diameter of varying length.
Thickness of the quill varies according
to grade (good quality: Not >
0.5mm), bark: 10-40mm.
External surface: is yellow-brown,
shining, wavy lines (pericycle fibres)
and occasional scars & holes
(leave/twig positions).
Inner surface: darker, longitudinally
striated.
Odour: fragrant
Taste: Warm, sweet & aromatic
MICROSCOPICAL FEATURES
 Transverse:
absence of epidermis & cork
 Sclereids (thickened lignified pitted walls)
 Secondary phloem is composed of phloem
parenchyma containing oil & mucilage cells,
phloem fibres & medullary rays.
 Some phloem parenchyma contain tannins.
 Secretion cells: volatile oils and mucilage
 Calcium oxalates
Cinnamomum - CONSTITUENTS
•
•
•
•
•
Volatile oils (at least
1.2 %)
Phlobaphenes
Mucilage
Calcium Oxalate
Starch
CINNAMON OIL –
ADULTERATION & ALLIED HERBS
Adulterants
• Cinnamon Leaf Oil
• Oil of Cassia
Allied Herbs
• Cayenne Cinnamon – C. zeylanicum grown in
Brazil – not used in Britain
• C. loureirii – from Vietnam – Closely resembles
C. cassia
Cinnamomum zeylanicum - USES
Flavouring agent
Mild astringent
Oil:
Carminative
Germicide
LEMON PEEL
Definition: Dried lemon
(Limonis Cortex) peel is
obtained from the fruit of
Citrus limon (Rutaceae).
Botanical Description:
Small tree, growing to 3-5 m
in height.
Geographical Sources
Mediterranean Regions
Limonis Cortex –
COLLECTION & PREPARATION
Lemons are collected in
January, August &
November, before the
green colour changes to
yellow.
The smaller fruit, which
would not be sold on the
produce market, are used
in the preparation of oil of
lemon - the peel is
removed with a sharp
knife in the form of a
spiral band.
Limonis Cortex –
CHARACTERISTICS
Dried lemon peel occurs
in spiral bands (2 cm
wide; 2-3 mm thick).
The outer surface is
rough & yellow; the
inner surface is pulpy
& white (anatomically
similar to that of an
orange peel).
Odour: Strong &
characteristic
Taste: aromatic & bitter
Limonis Cortex –
CONSTITUENTS & USES
CONSTITUENTS
Should contain at least
2.5% volatile oil
Vitamin C
Hesperidin (Flavonoid)
Mucilage
Calcium Oxalate
USES
Flavouring purposes
LEMON OILS - Oleum limonis
Definition: Lemon oil is the oil expressed from the outer part of
the fresh pericarp of the ripe or nearly ripe fruit of Citrus limon
(Rutaceae).
BP: oil should be obtained by suitable mechanical means, without
the use of heat, from the fresh peel.
Much oil is derived via steam distillation, but this process yields
oil of inferior quality.
Distilled oil of lemon is much cheaper than that prepared by
expression. Large amounts are used for non-pharmaceutical
purposes.
Geographical Sources:
Mediterranean, North & South America, Australia & parts of Africa.
Preparation of Lemon Oils
i. Hand Methods
No longer applicable to
pharmaceutical oils
Production of Lemon Oils
Machine Processes
Quality is inferior to the best hand-pressed oils.
Machines are designed to release oils from the peel via puncture,
rasting or cutting and by imitating the gentle squeezing action
of the sponge method. (Superiority of the sponge method is
due to the fact that there is no contact between the oil & the
inner white part of the skin.
The newer machines extract oil more completely than the older
ones and give a higher yeild
ii.
Distilled Oils
Although not official, some lemon oils are produced by distillation,
mainly from the residue of the expression processes. It is
much cheaper than hand-pressed or machine-made oil.
iii.
Oleum limonis - CONSTITUENTS
Terpenes – mainly limonene
Sesquiterpenes
Aldehydes (Citral & Citronella)
Esters
Lemon oil has a tendency to resinify and
should be protected from the action of air
& light as much as possible.
Oleum limonis –
ADULTATION & USES
ADULTERATION
Oil of turpentine
Terpenes from ‘terpeneless
oil of lemon’
Distilled oil of lemon
Oil of lemon-grass
USES
Perfumery
Flavouring
TERPENELESS LEMON OIL
Definition: Oil prepared by
concentrating lemon oil in
vacuum until most of the
terpenes have been
removed, or by solvent
partition. The
concentrate is a
terpeneless oil, which has
a citral content of 40-50
%.
It is equal in flavouring to
10-15 times its volume of
lemon oil
BUCHU – Agathosma betulina
Agathosma betulina –
CONSTITUENS & USES
CONSTITUENTS
Volatile oils
• Pulegone
• Menthone & isomenthone
• limonene
Diosmin
Mucilage
Resin
Calcium oxalates
Buchu camphor – Responsible for the diuretic action
USES/ACTIONS
Diuretic
Urinary Tract Anti-Septic – Used for UTI’s
NUTMEG & NUTMEG OIL
Definition: Nutmeg is the
dried kernel of the seed
of Myristica fragrans
(Myristicaceae).
Geographical Sources
Indigenous to the Molucca
Islands (Spice Islands)
Cultivated in Indonesia,
Malaysia & the West
Indies.
NUTMEG – Myristica fragrans
HISTORY
First Introduced to the
Europeans by the Arabs.
Portuguese lost control of
the spice trade to the
Dutch, who maintained
complete monopoly by
destroying all trees in the
neighbouring islands &
preventing the export of
living seeds.
CULTIVATION, COLLECTION &
PREPARATION
Trees can be grown from fresh seed
gown in the shell. The seeds
germinate after about 5 weeks.
When the plants are 6 months
old, they are transplanted to the
fields.
Nutmegs are dried in the shells
(process differs according to local
conditions). Normally they are
dried in the sun & covered at
night & rainy weather. They can
also be dried in the oven or over
low flames.
When completely dried, the kernel
rattles in the testa, which is then
cracked & the nutmeg extracted.
MACROSCOPICAL FEATURES
Nutmeg trees are
evergreen, growing up to
20 m in height.
Nutmegs are oval, 2-3 cm
long & 2 cm broad.
If not heavily limed, the
surface is a brown or grey
brown in colour.
Odour: Strong & aromatic
Taste: Pungent and slightly
bitter.
MICROSCOPICAL FEATURES
Potassium acid tartrate
crystals
Parenchym with thin
brown walls
Oval oil cells
Feathery crystals of fat
Few tannin cells
(containing tannin &
starch)
NUTMEG – ALLIED HERBS
Papua nutmegs –
from M. argentea
(New Guinea) – little
odour & a
disagreeable taste.
Bombay nutmegs –
M. malabarica (India)
– lack the
characteristic odour of
the genuine herb.
NUTMEG OIL
Nutmeg oil is distilled from the
kernels of Myristica fragrans.
CONSTITUENTS
Pinene
Sabinene
Camphene
Dipentene
Safrole
Eugenol & eugenol derivatives
Myristicin – a benzene: toxic to
humans (large does of nutmeg
or nutmeg oil may cause
convulsions).
MACE
Common mace or Banda
mace consists of the
dried arillus or arillode of
M. fragrans.
Description: bright red
colour & lacks in aroma.
MACE – CONSTITUENTS & USES
CONSTITUENTS
Volatile oils (similar to that
of nutmeg) – eugenol
derivatives are the main
active constituents –
responsible for the antibacterial effects.
Also has 2 anti-microbial
resorcinols (Malabaricone
B and C)
Nutmegs, maces & their
oils, are all used for
• Carminatives
• Flavouring
• Infantile Diarrhoea (Tea
of nutmeg – Ayurveda).
CLOVE
DEFINITION: Cloves are
the dried flower buds of
Syzygium aromaticum
(Eugenia caryophyllus),
(Myrtaceaea).
Geographical Sources
Molucca or Clove Islands,
Zanzibar, Pemba,
Madagascar, Indonesia &
Brazil.
HISTORY OF CLOVE
Cloves were used in China as
early as 266 BC, and by the
4th century, they were known
in Europe, although very
expensive.
Same as with nutmeg, the
Dutch also destroyed all trees
from surrounding native
islands to secure a
monopoly, and cultivated
them only in a small group of
islands.
In 1770, the French managed to
introduce clove trees to
Mauritius, and started
cultivating them there, as well
as in Zanzibar, Penang and
Sumatra.
COLLECTION & PREPARATION
The flower buds are
collected when the lower
part turns green-crimson.
The cloves are dried in
the open air on mats &
separated from their
peduncles (forming clove
stalks which are also sold
commercially).
If left on the tree for too
long, the buds open & the
petals fall, leaving “brown
cloves”. Later the fruits
(“mother cloves”) are
produced.
MACROSCOPICAL FEATURES
Cloves are 10-17.5 mm
long.
The head consists of 4
slightly projecting calyx
teeth, 4 membranous
petals and numerous
incurved stamens around
a large style.
Odour: Spicy & Pungent
Taste: Aromatic
MICROSCOPICAL FEATURES
Heavy cuticularized epidermis
Numerous oil cells (shizolysigenous)
Calcium oxalates (cluster crystals & prisms)
Stomata (epidermis of sepals)
Starch (Fruit – “mother cloves”)
Lignified sclereids
CONSTITUENTS
14-21% Volatile oils
• Mainly eugenol & isoeugenol
• Sitosterol
• Stigmasterol
• Campesterol
Tannins
Triterpene acids & esters
Glycosides
USES OF CLOVE
Stimulant aromatic
Spice
For the preparation of
volatile oil
Sesquiterpenes:
potential anticarcinogenic
compounds
CLOVE OIL
Oil distilled in Europe
and the US normally
does not need
purification, while oil
distilled in other areas
(e.g. Madagascar)
does. After
purification the oil is
sold with varying
eugenol contents.
Oil of cloves is yellow or
colourless, is slightly
heavier than water.
CLOVE OIL - CONSTITUENTS
Volatile oils – mainly eugenol & acetyleugenol
Sesquiterpenes (α and β caryophyllenes)
Oil of clove – like other volatile/essential oils –
should be stored in a well-fitted, air-tight
container, & should be protected from light &
heat.
CLOVE OIL - USES
Anti-septic
Aromatic
Stimulant
Flavouring Agent
EUCALYPTUS LEAF
DEFINTION: Eucalyptus
leaf consists of the whole
or cut dried leaves of the
older branches of
Eucalyptus globulus,
(Myrtaceae).
GEOGRAPHICAL
SOURCES
Portugal, SA, Spain, China,
Brazil, Australia, India &
Paraguay.
Eucalyptus - DESCRIPTION
MACROSCOPICAL
• Older dried leaves are
grey-brown & have lateral
veins. Secretory oil cells
are visible in leaves held
to the light.
MICROSCOPIC
• Epidermal cells have a
thick cuticle.
• Anisocytic stomata
• Mesophyll has
schizogenous oil glands
• Calcium oxalate crystals:
Prisms & Cluster crystals
Eucalyptus - CONSTITUENTS
Volatile Oil (at least 2
%)
sesquiterpene - Antibacterial action
against oral
pathogens.
EUCALYPTUS OIL
Oil of eucalyptus is distilled from the fresh leaves
of various species of Eucalyptus and rectified.
They are produced in the same countries which
produce the dry herb.
Only a certain amount of species produce oil
suitable for medicinal use – the main criteria is a
high cineole content and low amounts of
phellandrene and aldehydes.
Suitable oils are obtained from E. polybractea, E.
smithii, E. globulus and E. australiana.
CHARACTERISTICS &
CONSTITUENTS
CHARACTERISTICS
Colourless or pale yellow
liquid
Aromatic & camphoraceous
in odour.
Pungent & camphoraceous
in taste, which is followed
by a sensation of cold.
CONSTITUENTS
At least 70 volatile oils
(mainly cineole).
EUCALYPTUS OIL - USES
Alleviating the symptoms of
nasopharyngeal
infections
Treating coughs
Decongestant.
Official preparations
Mixtures, inhalations,
lozenges and pastilles;
also applied externally as
ointments and liniments.
FENNEL
DEFINITION: Fennel
consists of the dried ripe
fruits of Foeniculum
vulgare (Umbelliferae).
GEOGRAPHICAL
SOURCES
Europe, India, China &
Egypt. Mediterranean
origin.
ACTIVE CONSTITUENTS
1-4 % Volatile oil
• trans-anethole
• Antethole
• Estragole
• Fenchone
Flavonoids
Coumarins
Glycosides
ACTIONS & USES
ACTIONS
• Carminative
• Expectorant
• Aromatic
- All due to anethole (and
fenchone)
USES
Flatulence
Dyspepsia
Chronic coughs & catarrh
Foeniculum vulgare
Foeniculum vulgare – USES
Culinary purposes
Used in medicine as a
flavouring
Carminative
CARAWAY & CARAWAY OIL
DEFINITION: Caraway
consists of the dried, ripe
fruits of Caram carvi
(Umbelliferae).
GEOGRAPHICAL
SOURCES
Wild & Cultivated in Central
& Northern Europe,
Holland, Denmark,
Germany, Russia,
Finland, Poland,
Hungary, Britain, Egypt,
Morocco, Australia &
China
MACROSCOPICAL FEATURES
A biennial herb growing up
to 1 m in height.
Herb: Normally consists of
mericarps separated from
the pedicels. Fruits are
slightly curved, brown &
glabrous.
Size: 4-7 mm long, 1-3 mm
wide
Often the stigma & style are
still attached.
Characteristic aromatic
odour & taste
MICROSCOPICAL FEATURES
Pitted sclerenchyma
secretory canals
Dark, red-brown cells
containing a pale
yellow or colourless
oleoresin
Thick cellulose walls
Calcium oxalate crystals
ACTIVE CONSTITUENTS
1-7 % Volatile oils
• Carvone
• Limonene
• Carveole
8-20 % Fixed oils
Proteins
Calcium oxalates
Colouring matter
Resin
CORIANDER & CORIANDER OIL
DEFINITION: Coriander is
the dried, nearly ripe fruit
of Coriandrum sativum
(Umbelliferae).
GEOGRAPHICAL
SOURCES
Indigenous to Italy. Also
cultivated in Holland,
Central & Eastern
Europe, Mediterranean
(Morocco, Malta &
Egypt), China, India &
Bagladesh.
MACROSCOPICAL FEATURES
Annual herb growing 0.7 m
in height with white or
pink flowers.
Drug: Normally consists of
whole cremocarps –
straw yellow & 2-4 mm in
diameter when ripe.
Considerable variation
occurs (e.g. Indian variety
> oval).
Apex has 2 styles.
Fruits have an aromatic
odour & spicy taste.
Unripe plant: unpleasant
mousy odour  same
odour oil has when made
from unripe fruit.
MICROSCOPICAL FEATURES
Outer pericarp: stomata
& calcium oxalte
prisms.
Thick sclerenchyma
Testa:= brown flattened
cells
Endosperm is curved &
consists of
parenchymous cells
containing fixed oils.
ACTIVE CONSTITUENTS
1.8 % Volatile oils
• Linalool/coriandrol
• Pinene
• Terpinene
• Limonene
• Cymene
• Non-linalool alchols & esters
Flavonoids
Coumarins
Phenolic acids
High fat content (16-28%)
Protein (11-17%)
Coriandrum sativum - USES
Domestic purposes
(cooking - curries)
Pharmaceutically:
flavouring agent &
Carminative
PEPPERMINT
& PEPPERMINT OIL
DEFINITION:
Peppermint is the
dried leaves of
Mentha piperita
(Labiate). It should
contain at least 1.2 %
volatile oil.
GEOGRAPHICAL
SOURCES:
Europe & America
MACROSCOPICAL FEATURES
All mints have a square
stem & creeping rhizome.
Black mint, which is the
most commonly cultivated
variety in England, has
purple stems and dark
green petiolate leaves
tinged with purple. Leaf
blades are 3-9 cm long
with a grooved petiolate
up to 1 cm long.
Pinnate venation.
Glandular trichomes: bright
yellow points (hand lens)
Small purple flowers appear
in late summer.
MICROSCOPIC FEATURES
Diacytic stomata
Multicellular clothing
trichomes
2 types of glandular
trichomes (one with a
unicellar head; with a
multicellular head).
Calcium oxalate is
absent.
Oleum Menthae
Oil of peppermint is
obtained from Mentha
piperita via steam
distillation using the
flowering tops.
Oil should contain at
least 44 % menthol,
15-32 & menthone
and 4.5-10 % menthyl
acetate.
Oleum Menthae - CONSTITUENTS
Menthol
Menthone & isomenthone
Menthyl acetate
Limonene
Cineole
Menthofuran
Pulegone
Cineole
OIL COMPOSITION: greatly
influenced by genetic
factors & seasonal variation.
PEPPERMINT & PEPPERMINT
OIL USES
OIL: anti-bacterial,
cooling, carminative
HERB: Carminative
LESSON TAKE-AWAY

Definitions of Volatile
Oils
 Methods of
Production of Volatile
Oils
 Herbs containing
Volatile Oils