QUESTIONS
Q1. What are essential oils?
Q2. Describe different methods of extraction of volatile oils?
Q3. Describe the chemistry of essential oils?
Q4. How are volatile oils classified?
Q5. Discuss biosynthesis of any main constituent of volatile oils you have studied?
Q5. Significance of volatile oils in plants?
Q6. Difference b/w essential oils and fixed oils?
Q7. Write a detail note on production and use of camphor?
EUCALPYTUS
B.O Eucalyptus globulus Labillardiere.
Family Myrtaceae.
P.U Dried leaves.
Constituents:
It contains colourless or pale yellow oil which is about 6%, having an aromatic odour, spicy cooling taste, containing 70% of cineole C10H18O, d- pinene and other terpenes, resins, a bitter principle and tannin, eucalyptic acid, Ca-oxalate etc.
Uses:
It is used as carminative, expectorant, rubifaciant, antiseptic, and diaphoretic (agent intended to induce sweating).
Ester Volatile Oils
A wide variety of ester occurs in volatile oils. The most common are the acetates of terpineol borneol and geranial. Other examples of esters in volatile oils are allyl isothiocyanate in mustard oil and methyl salicylate in wintergreen oil.
ANETHUM
B.O Anethum graveolens.
Family Umbelliferae.
P.U Dried ripe fruits.
Constituents:
The fruit yields about 3-4% of volatile oil, which should contain from 43-605 of carvone. It also contains limonene.
Uses:
Carminative, Flavouring agent.
ROSEMARRY
B.O Rosmarinus officinalis.
Family Labiatae.
P.U Flowering tops.
Constituents:
The fresh material yields about 1-2% of volatile oils containing esters (0.8-6% calculated as bornyl acetate)
Uses:
The oil is an ingredient of soap liniment. Used to impart good smell to the formulations. And in perfumery industry.
A no of phenolic ether occurs in volatile oils such as anethol from anise and fennel, Safrole from sassafras etc.
“ANISE”
B.O Pimpinella anisum
Family Umbelliferae
P.U Dried ripe fruit.
Habitat: Found in
Constituents:
Anise contains volatile oil (1-3%), consisting of about 80-90% of anethol; fixed oil, Ca-oxalate crystals, proteins, and sugars.
Uses:
Anise is used as carminative, flavouring agent, condiment and stimulant.
“FENNEL”
B.O Foeniculum vulgare.
Family Umbelliferae.
P.U Dried ripe fruit.
Habitat:
Found in
Constituents:
It contains volatile oils about 1-4% the chief constituents of which are anethole (50-60%) and fenchone.
Uses:
It is used as carminative, stimulant, and flavouring agent.
“NUTMEG”
B.O Myristica fragrans Houttuyn
Family Myristacaceae.
P.U Dried ripe seeds.
Habitat:
Found in
Constituents:
It contains volatile oil, 8-10% that contains myristicin and safrole. It also contains a narcotic principle pinene, camphene and traces of eugenol along with starch and proteins.
Uses:
It is used as stimulant, carminative and flavouring agent.
Phenols present in volatile oils are of two types.
1. These which are present naturally.
2. These produced as a result of destructive distillation of certain plant product
Important phenols present in volatile oils are eugenol, thymol and carvacrol.
“CLOVE”
B.O Eugenia caryophyllus.
Family Myrtaceae.
P.U Dried flowering buds/ unopened flowers.
Habitat:
It is indigenous to Molucca.
Constituents:
About 14-21% of volatile oils comprises of Eugenol, acetyleugenol.
Sesquiterpenes (a- and b-caryophyllenes), gallotannic acid, vanillin and Ca- oxalate etc.
Uses:
Clove is used as stimulant, aromatic carminative and as a condiment. It is the most stimulating and carminative among all the aromatics.
It is used for the emesis, nausea in the form of infusion or powder.
Oil of clove is powerful irritant and antiseptic. It is also used as local anesthetic and often being applied for decaying teeth and has been used with success for bronchial asthma.
“THYME”
B.O Thymus vulgaris.
Family Labiatae.
P.U Dried leaves and flowering tops.
Constituents:
It contains thymol, carvacrol, cymene, thymene and d-pinene.
Uses:
It is used as antispasmodic, carminative, stimulant, and condiment in flavouring of meat and fish dishes.
1. Monocyclic ketone terpenes:
e.g. Menthone, carvone, piperitone, pulegone and diosphenol.
2. Dicyclic ketone terpenes:
e.g. Camphor, fenebone and thujone
GUM CAMPHOR
B.O Cinnamomum camphora (L) Nees
Family Lauraceae.
P.U wood of stem and root is used for distillation of camphor. It is also produced synthetically.
Habitat: Plants are found in
Commerce and production:
Camphor is produced synthetically from turpentine.
HCl Sodium acetate
Pinene ---------------------- Bornylchloride ------------------------ Bornyl acetate
Bornyl acetate ----------- Isobornyl acetate
Isobornyl acetate ------- Hydrolysis ------- Isoborneol -----Oxidation-------- Camphor
The best yield of camphor is obtained from trees of 50 years old. Young branches and twigs are chopped up which are placed in wooden still, covered with 6 inch layer of earth. It is heated in an iron pan placed under the wooden still. Second end of wooden still is connected with a bomber tube which opens into a tub made of wood. One tub is placed over the other. Water accumulates in lower and sublimation of camphor is deposited on the lower surface of upper tub. After full circulation the sublimation is removed. It requires about 12-hours to distill one complete still of camphor 20-40 lbs. Of chips are required to get 1 lb. of crude camphor.
Properties:
It is white crystalline colourless and transparent material. It has characteristic odour and pungent aromatic taste, which is followed by a sensation of cold. It volatilizes at ordinary temp. natural camphor is dextro-rotatory and synthetic product is almost optically inactive.
Constituents:
Main constituent is a ketone having formula C10H11O.
Uses:
It is internally used as a mild antiseptic and carminative. It is employed externally in the form of spirit or liniment as a rubefacient.
It is also used in the manufacture of celluloid and peroxy plastics.
“SPEARMINT”
B.O Mentha spicata
Family Labiatae.
P.U Dried leaves and flowering tops.
Constituents:
Oil of spearmint contains carvone limonene, phellandrene and esters.
Uses:
Carminative, Flavouring agent, used in chewing gum.
“CARAWAY”
B.O Carum carvi
Family Umbelliferae
P.U Dried ripen fruit.
Constituents:
Contain volatile oil, carvone, limonene, dihydrocarvone, fixed oils and tannins.
Uses:
Stimulant, carminative, condiment, flavoring agent.
“BUCHU”
B.O Barosma betulina
Barosma crenulata
Family Rutaceae.
P.U Dried leaves.
Constituents:
It contains volatile oil with peppermint like odour containing diosphenol.
Uses:
Used as disinfectant for urinary tract in cystitis, for inflammation of prostate gland, used as diuretic and antiseptic.
These may be classified as
1. Acyclic: e.g. Geraniol, Neral, and Citronellol.
2. Cyclic: e.g. Cinnamaldehyde, Vanillin, and anisaldehyde.
CINNAMON
There are two varieties;
Family Lauraceae.
P.U Dried inner bark of the shoot.
Habitat
Commerce:
The fresh seeds are sown in seedbeds. The plants are than arranged with about 6-10 ft. apart. When they are six months old, about 5-6 shoots are then allowed to grow from the stump and kept straight by pruning. The young stems are then cut down to a few inches about the ground and allowed to form stools from which adventitious but arise. These buds develop into adventitious shoot, which lengthens at the rate of about 1m per year. When the shoots are about 2m long they are cut down during the rainy season and brought to the shade where leaves and small twigs are removed. The outer bark is then is then scrapped off with curved knives. Longitudinal incision of about 6-8 inch is made, through the soft inner bark carefully, to the cambium line and the inner bark is removed with care from the hard wood as quills.
A long stick of compound quills is then formed by placing 7—12 soft white quills together to form a tube about one yard long and then rolled by hand, placed on mats and then allowed to dry successively for three days in sun and three days in shade. During drying the original white colour of the bark turns into a yellowish brown or weak orange colour. The quills are then made into bundles and tied with split bamboo.
The quills are chiefly rolled, composed of 7—12 or thinner layers of inner bark which are often 1m long. The bark is 1mm thick. The outer surface is light yellowish brown to weak orange, smooth longitudinally, striated and showing circular or irregular brown patches. Inner surface is light yellowish brown to weak orange with faint longitudinally striation,
CONSTITUENTS: -
Cinnamon contains volatile oil about 2% containing Cinnamic aldehyde, cryophylline, resin mucilage, starch, tannins and ca-oxalate.
USES: -
1. Aromatic 2. Flavoring agent 3. Carminative
BITTER ORANGE PEEL:
B.O: - Citrus aurantium
SWEET
B.O: - Citrus sinesis
LEMON PEEL:
B.O:- Citrus limon
Family: - Rutaceae
P.U :- Dried outer part of pericarp of ripe fruit.
CONSTITUENTS:-
Bitter orange peel: 2.5% of volatile oil, vit. C and flavonoid glycosides, hesperidin and neoheperidin.
Sweet orange peel: - Volatile oil having d-limonene dicyclic aldehyde, methyl anthranilic acid and flavouring glycosides along with hesperidine.
Lemon peel: - lemon peel contains not less than 2.5% of volatile oil. Lemon oil contains terpenes moity, d-limonene, citral, citronellol and ca-oxalate.
USES: -
1. Carminative 2. Aromatic 3. Flavoring purposes.
Alcohols found in volatile oil may be classified into three groups.
1. Acyclic Alcohols:
Methyl, ethyl, isobutyl, isoamyl, hexyl and higher aliphatic alcohols are present in volatile oils but they are washed away during the process of steam distillation as they are soluble in water. However any volatile oils contain acyclic alcohols of terpene nature such as geraniol, linalol, litronellol etc.
2. Monocyclic alcohols:
Among the monocyclic alcohols, the important ones are a-terpenol, menthol.
3. Bicyclic alcohols:
Borneol is bicyclic terpene alcohol from borneo camphor.
This group includes zingiberol.
“PEPPERMINT”
Syn
B.O Mentha piperita
Family Labiatae.
P.U Dried leaves and flowering tops.
Habitat:
This plant is found through out the country along the stream banks and wasteland areas. It is cultivated in some parts of
Constituents:
About 1% of L volatile oil containing 78% of free menthol and up to 20% of menthol combined as ester, resin, and tannin and with acetic acid.
Uses:
Carminative, stimulant, and as flavoring agent.
From its carminative and stimulant properties, it is valuable in certain forms of dyspepsia and is also used in flatulence and colic.
Peppermint water and spirit of peppermint are official preparation of B.P. Oil of peppermint is a powerful antiseptic and has local anaesthetic action. These properties make it valuable in the relief of toothache and in the treatment of cavities in the teeth.
“CARDAMOM”
B.O Elettaria cardamomum.
Family Zingiberaceae.
P.U Dried ripened seeds recently removed from capsule. The dried and rip fruit or capsule is used to avoid loss of volatile components from seeds.
Habitat:
In mountainous distances of
Production and commerce:
The plants are propagated by division of rhizomes or by seeds, planted in nursery beds. Seedlings are then transported in the shade of trees nearly 7 ft. apart. They begin to bear fruit in their third year.
Fruits are gathered before maturity when they start to turn to yellow. Either the entire raceme is cut as in Syria or only the ripen fruit may be cut off with scissors from the stalk as in Ceylon, dried by the sun or the fruits are stripped off and are dried on mats, in several days by aid of gentle fire, heat, cleaned with the help of machines to remove calyx and pedicle. Then graded by sieve, bleached by exposure to dew and sunlight, or imposing to SO2 and steam. Finally dried in the sun. Drug is marketed both as capsules and as seeds.
Several varieties of capsules, which are classified into groups, based on their size and commercial source.
Based on there size, there are three types.
1. Short, length is 12mm, and is 6mm broad.
2. Short long, L= 18mm, W=6mm.
3. Long, L=30mm, W=4mm.
According to commercial varieties seeds are named as.
1. Mysore/Ceylon
2. Malabar/Ceylon Malabar Variety: is usually smaller and have a rather darker and less smooth pericarp.
3. Mangalore: resemble Malabar, but are usually more globular and have globular and have a rough pericarp.
4. Alleppy: Fruits are narrower than other varieties, vary in colour from greenish-buff to green. These are considered best for the process of distillation.
Constituents:
3-3.5% of volatile oil called cardamom oil containing terpinol, terpinyl acetate, borneol, fixed oil, proteins and ca-oxalate.
Uses:
Used as carminative, aromatic, condiment, and flavoring agent and for flatulence and indigestion.
“CORIANDER”
B.O Coriandrum sativum
Family Umbelliferae.
P.U Dried ripe fruit.
Habitat Cultivated in central and Eastern
Constituents:
It contains 1.8% of volatile oil containing coriander and d-pinene, fixed oil and Ca-oxalate.
Uses:
Flavoring agent, condiment, carminative, Aromatic stimulant.
Syn Tailed pepper.
B.O Piper cubeba
Family Piperaceae.
P.U Dried fully-grown unripe fruit.
Habitat Java, Smatra, Srilanka and other parts of
Constituents:
It yields about 10-18% of volatile oil containing terpenes and sesquiterpense, resins, amorphous cubebic acid and colourless crystalline compound cubebin. Cubebic acid is coloured purple red when treated with H2SO4 while cubebin is coloured cherry red with the same reagent.
Uses:
Diuretic, Expectorant, Genito-urinary antiseptic. It is used as remedy for gonorrhoea after acute inflammation. It is also used in cystitis, piles and chronic bronchitis.
TERPENTINE OIL
Syn Oil of turpentine
Turpentine tincture
Turpentine spirit.
B.O Pinus Longifolia Roxb.
Pinus roxburghii Sargent.
Pinus excelsa wall.
Family Pinaceae
Order Coniferales
Class Coniferopsida.
Sub. Division Gymnosperm
Tracheophyta (Spermophyta)
P.U Oleoresin obtained from plant.
COLLECTION:
Pinus oleoresin is a normal i.e. physiological product of pine. The amount produced is generally enhanced by injury or by treatment with 50% H2SO4. It is secreted in plant tissues in specific cavities or resin ducts. These ducts are frequently located directly beneath the cambium in the sapwood marked by a distinct layer of secretary cells. This is called resinogerious layer, secrete the resin into the cavity through a thin circular integument. The cavities are themselves formed either in a schizogenous or lysigenous fashion.
These are anastinosing in nature. When one of the passages is open as in wound from a distance. The acid treatment crumpled the thin walled parenchyma.
This permits the duct channel to become larger providing a more rapid flow of oleoresin and two methods of collection have been used;
1. Box method.
2. Cup and gutter method.
BOX METHOD:
It is very old method, which was previously used in many countries. A large box was cut in the trunk and blaze cut about it. The length of which was increased from time to time. The oleoresin, which was collected in the box, was removed at intervals with a dipper and sent in barrels to the distillery. This method is often baseful causing destruction of most areas.
CUP AND GUTTER METHOD:
This method with different modifications is used in different countries. A series of ‘V’ shaped incisions are made in the trunk of the tree of a distance of about one-foot. The bark and young wood being removed so that a blaze or a groove is formed in the trunk. This is usually done early in the year. At the base of incision and aluminium earthen ware cup is fixed in the trunk and two strips of galvanized iron or aluminium are inserted about to deflect the flow of oleoresin into the cup. The length of the blaze is increased and the cups are moved higher up the trees and now grooves are started with the older ones. As the cups become filled, their contents are emptied into the barrels, which are delivered to the distillery where the turpentine oil is removed by steam distillation, and the resin become rosin.
CHARACTERISTICS:
Turpentine oil is colourless liquid possessing a characteristic odour and taste. It is soluble in alcohol and has a specific gravity of 0.854-0.868 at 25C.
CONSTITUENTS:
Turpentine consists of Dicyclic monoterpenes such as d & L a-pinene and camphene. It also contains monocyclic monoterpenes such as dipentene and methyl carbachol and also bormyl acetate etc.
USES:
Turpentine oil is now rarely given internally. Externally it is used as counter irritant, rubifaciant in lotions, also as mild antiseptic. It is also used as solvent for waxes in the production of synthetic camphor, shoe polishes and furniture polishes.
RECTIFIED OIL OF TURPENTINE:
It is turpentine oil rectified by distillation from an aqueous solution of NAOH and terpinol oil. Terpinol oil is found by the action of nitric acid on rectified turpentine oil in the presence of alcohol. Rectified turpentine oil and terpinol both are used internally as diuretic, urinary antiseptic, antihermatic, and expectorant.
Turpentine oil itself is used in industry as solvent for waxes in the production of synthetic camphor, shoe polish and furniture polish.
Following are the divisions in which volatile oils and volatile containing drugs are placed.
1. Hydrocarbon volatile oils: e.g. Cubeb, Turpentine oil
2. Alcoholic volatile oils: e.g. Peppermint, Cardamom, and Coriander.
3. Aldehyde volatile oils: e.g. Bitter orange peel, lemon peel, and sweet orange peel.
4. Ketonic volatile oils: e.g. Camphor, spearmint, and caraway.
5. Phenolic volatile oils: e.g. Clove, Thyme.
6. Phenolic ether volatile oils: e.g. Fennel, Anise, and Myristica.
7. Oxide volatile oils: e.g. chenopodium, eucalyptus.
8. Ester volatile oils: e.g. Rose merry oil.
9. Miscellaneous: e.g. Allium, Anthum.
1. Hemiterpenes:
Hemiterpenes are the compounds having 5-carbon atoms i.e.
a. Isoamyl alcohol:
Found in mentha spp.
b. Isovaler aldehyde:
Found in eucalyptus.
2. Monoterpenes:
These are composed of two isoprene units and have the formula C10H16. Monoterpenes are further classified as
a. Open chain or Acylic hydrocarbons.
b. Monocyclic hydrocarbons.
c. Dicyclic hydrocarbons.
d. Tricyclic monoterpenes.
3. Sesquiterpenes:
These contain three isoprene units having the molecular formula C15H24. Sesquiterpenes may be;
a. Acyclic or open chain e.g. Farnesol.
b. Monocyclic e.g. Zingeberene.
c. Dicyclic e.g. Cadinine.
4. Diterpenes:
Diterpenes have four isoprene units and have the molecular formula C20H32. Diterpenoid compounds include such resin acids as + and – pimaric acid and their isomer, the abietic acid of pine resin. Many diterpenoids (e.g. vit A and gibberellic acid) do not belong to the volatile oil-resin group.
Acyclic Diterpenes :
Phytol is an unsaturated alcohol, a component of the chlorophyll molecule. Phytol has following formula.
Monocyclic Diterpenes:
a-camphorene
Dicyclic Diterpenes:
e.g. Agathic acid found in Agathis alba
Tricyclic Diterpenes.
e.g. Abietic acid and Pimaric acid
Tetracyclic Diterpenes.
e.g. Phylleladene
5. Triterpenes:
These are abundant in nature particularly in resins and may occur as either esters or glycosides. They may be aliphatic e.g. squalene, tetracyclic or pentacyclic. Tetracyclic’s examples are Limonoids, sterols and pentacyclics examples are b-amyrin, 4,4-dimethyl sterol.
6.Tetraterpenes: (C= 40)
These are mainly cartenoids pigments. The important pigments are orange red and yellow. These are found along with chlorophyll in photosynthetic tissues and are located in chloroplast lamella.
The colour of red tomato and the orange are due to the lycopene.
Polyterpenoids:
These are compounds of many isoprene units e.g. rubber.
Rubber is a polyterpenoid product in latex of about 300 genera of angiosperm but only Hevea brasiliensis is used. Rubber is manufactured in
Mixed Terpenoids:
Mixed Terpenoids compounds consist of terpenoid and non-terpenoid components other than sugar and fatty acids e.g. Terpenoid glycosides and terpenoid esters.
Stereopenes:
Another major group of volatile oils is stereopenes or phenyl propanoids. These compounds contain C=6 Phenyl ring with an attached c=3 propane side chain. Many of the phenyl propanoids found in volatile oils are phenols or phenol esters. Some of the famous examples are Cinnamaldehyde, anethole, eugenol, and phenyl ethyl alcohol, anisaldehyde and methyl salicylate.
These compounds form of oil in some spp. While in other spp. The hydrocarbon liquid portion predominates. The odour and the taste of ess. Oil is mainly determined by the oxygenated components which are usually soluble in water but more soluble in alcohol. They can further be classified as.
1. Open chain or Acentric.
2. Monocyclic.
3- Dicyclic:
