Volatile Oils: Overview, Extraction Methods

• Essential oils

• Ethereal oils

• Olea aethereal

• Essences

Volatile Oils are also known as

• Colorless

• Freely soluble in ether and chloroform; fairly soluble in alcohol; Insoluble in water.

• Lighter than water

• Characteristic odor

• High refractive index

• Optically active

• Do not leave permanent grease spot on paper(Determines if volatile/fixed oil)

Characteristics of Volatile Oils

Volatile Oil

Volatile Oil or Fixed Oil?

Can be distilled from their natural sources

Fixed Oil

Volatile Oil or Fixed Oil?

They oxidized and become rancid

Fixed Oil

Volatile Oil or Fixed Oil?

Composed mainly of glyceryl esters of fatty acids

Volatile Oil

Volatile Oil or Fixed Oil?

Do not consists of glyceryl esters of fatty acids

Volatile Oil

Volatile Oil or Fixed Oil?

Cannot be saponified with alkali

Volatile Oil

Volatile Oil or Fixed Oil?

Do not become rancid but instead oxidize and resinify upon exposure to light and air

Fixed Oil

Volatile Oil or Fixed Oil?

Cannot be distilled without decomposition

Fixed Oil

Volatile Oil or Fixed Oil?

Leaves a permanent spot/strain on paper

Fixed oil

Volatile Oil or Fixed Oil

Can be saponified

Volatile Oil

Volatile Oil or Fixed Oil?

Do not leave a permanent spot on paper

• Glandular hairs or Trichomes

Specialized Secretory Structures

Lamiaceae (mint family)

Modified parenchymal cells

Specialized Secretory Structures

Piperaceae (Pepper family)

Oil tubes/ Vittae

Specialized Secretory Structures

Umbelliferae/Apiaceae (dillweed family)

Lysigenous or Schizogenous passages

Specialized Secretory Structures

Pinaceae (Pine family) / Rutaceae (Citrus family)

All tissue of plant

Conifers

Petals

Rose

Bark and leaves

Cinnamon

Petal and rind

Orange

• Extraction by distillation

• Extraction by Scarcification

• Extraction by Non-volatile solvent

• Extraction by Volatile Solvent

• Extraction by Enzymatic hydrolysis

Method of obtaining volatile oils

• Water distillation

• Water and steam distillation

• Direct steam distillation

• Destructive distillation

Extraction by distillation

• Lard

• Olive oil

Examples of non-volatile solvent

Extraction by distillation: Water distillation

plant material that is dried and not subject to injury by boiling (eg. turpentine oil)

Extraction by distillation: Water and Steam Distillation

for dried or fresh substances that may be injured by boiling (eg. clove oil, cinnamon)

fresh plant drugs (eg. peppermint, spearmint)

Extraction by distillation: Steam Distillation

empyreumatic oils (heat w/o air access)

Extraction by distillation: Destructive Distillation

Incineration

Destructive distillation involves?

pinaceae/cupressaceae (conifern family)

In Destructive Distillation, the wood of ______ is used to make charcoal

• Aq layer containing wood nafta

• other layer?

In Destructive distillation, the condensed matter is separated into two layers:

• Sponge process

• Ecuelle Method

Extraction by Scarcification

Extraction by Scarcification: Sponge process

• Softening

• Expression

• Collection and Separation

• Controlled environment: Dark room

Extraction by Scarcification: Ecuelle Method

• Puncturing

• Washing

• Centrifugation

Ecuelle picquer

Extraction by Scarcification: Ecuelle Method is aka

Eceulle picquer

• method of obtaining citrus oils

• puncture rind not the fruit

• Enfleurage

• Maceration

• Spraying

Extraction by Non-Volatile Solvent

Extraction by Non-Volatile Solvent: Enfleurage

• Preparation: A thin layer of odorless, bland fixed oil or fat is spread onto glass plates.

• Absorption: Flower petals are placed on the fat for a few hours to allow the fat to absorb their fragrance.

• Repetition: Old petals are repeatedly removed and replaced with fresh ones to saturate the fat with the oil.

• Recovery: The final volatile oil is then extracted from the perfumed fat using alcohol

Extraction by Non-Volatile Solvent: Maceration

• Heating: The lard or oil is heated over a water bath.

• Stirring: Flowers are added to the hot fat and the mixture is stirred continuously.

• Replacement: Exhausted flowers are removed and pressed to return any absorbed fluid to the fat. This is repeated with fresh flowers until the solvent reaches the desired strength.

• Recovery: Finally, alcohol is used to extract the volatile oil from the perfumed fat

Extraction by Non-Volatile Solvent: Spraying

• Air Circulation: Warm air is sprayed through a column of flowers to pick up their fragrance.

• Absorption: Oil or melted fat is then sprayed over this fragrance-laden air, which absorbs and dissolves the perfume.

• Alcohol Extraction: Finally, the collected oil or fat is extracted with alcohol to recover the volatile oil.

Extraction by Volatile Solvent

Volatile oils from flowers are extracted by using the solvent light petroleum and is distilled at low temperature leaving behind the volatile oil

light petroleum

Extraction by Volatile Solvent: Volatile oils from flowers are extracted by using the solvent ____ and is distilled at low temperature leaving behind the volatile oil

• Petroleum ether

• Benzene

Extraction by Volatile Solvent: Other solvents used

Extraction by Enzymatic Hydrolysis

Obtained by enzymatic hydrolysis of glycosides

Black Mustard

Which is more volatile Black mustard or White mustard

Allyl isothiocyante

Extraction by Enzymatic Hydrolysis: Sinigrin upon hydrolysis yields what

Acrinyl isothiocyanate

Extraction by Enzymatic Hydrolysis: Sinalbin upon hydrolysis yields what

Myrosin

Extraction by Enzymatic Hydrolysis: Sinigrin and Sinalbin are facilitated by an enzyme called

Medicinal and Commercial Use of Volatile oils (Read)

• Most volatile

• Leave the skin rapidly

Fabrication of Perfumes: Top notes

• Intermediate volatility and tenacity

Fabrication of Perfumes: Middle Notes

• Low volatility and high tenacity

• Provide staying power for perfumes

Fabrication of Perfumes: Base Notes

• Lemon

• Anise

• Lavender

Tope Notes examples

• Thyme

• Rose

• Neroli

Middle Notes example

• Vanillin

• Musk

• Civet

• Ambergris

Base notes examples

• Musk

• preputial follicles

Dried secretion from the ____ of the male musk deer of Asia

Civet

A glandular secretion appearing in an outwardly discharging pocket underneath the posterior appendages of both male and female civet cats

Ambergris

A pathologic product formed in the stomach of the sperm whale when it is feeding on squid or cuttlefish (vomit of sperm whale) -> most expensive perfume!

Ambergris

Most expensive ingredient in perfume

• Eleoptene

• Stearoptene

Volatile oils consist of:

Eleoptene

hydrocarbon portion of the oil (liquid)

Stearoptene

oxidized hydrocarbon portion of the oil (solid)

• Low temperature: crystallize stearoptenes

• Fractional distillation

• Fractional crystallization from poor solvents

• Chromatography

• Removal by chemical reaction = NaCO3, HCL, NaOH

Ways to separate V.O components

• NaCO3

• HCl

• NaOH

Volatile Oil components can be separated by the removal of chemical action, give me 3 compounds.

• Terpene derivatives (Terpenoids)

• Aromatic compounds (Phenylpropanoids)

Chemistry of Volatile Oils

Terpene derivatives

formed via acetate mevalonic acid pathway

Aromatic compounds (phenylpropanoids)

Formed via shikimic-acid phenylpropanoid route

Shikimic-acid phenylpropanoid route

Aromatic compounds (Phenylpropanoids) are formed via what route

Acetate mevalonic acid pathway

Terpene derivatives (Terpenoids) form via what pathways

Terpenes

Natural products whose structure may be divided into isoprene units

(C5H8)n.

Most natural terpenoid hydrocarbons have the general formula ____ They can be classified on the basis of number of carbon atoms present in the structure.

Acyclic Terpenoids

Structure of Terpenoids: They contain an open structure

Monocyclic Terpenoids

Structure of Terpenoids: They contain one ring in the structure

Bicyclic Terpenoids

Structure of Terpenoids: They contain two rings in the structure

Tricyclic Terpenoids

Structure of Terpenoids: They contain three rings in the structure

Tetracyclic Terpenoids

Structure of Terpenoids: They contain four rings in the structure

Bonus

Bonus

• Monoterpenoids

• Sesquiterpenoids

• Diterpenoids

• Sesterpenoids

• Triterpenoids

• Tetraterpenoids

• Polyterpenoids

Classification of Terpenoids

• 10

• 2

Monoterpenoids

Number of carbon atoms:

Value of N:

• 15

• 3

Sesquiterpenoids

Number of carbon atoms:

Value of N:

• 20

• 4

Diterpenoids

Number of carbon atoms:

Value of N:

• 25

• 5

Sesterpenoids

Number of carbon atoms:

Value of N:

• 30

• 6

Triterpenoids

Number of carbon atoms:

Value of N:

• 40

• 8

Tetraterpenoids

Number of carbon atoms:

Value of N:

• >40

• >8

Polyterpenoids

Number of carbon atoms:

Value of N:

Phenylpropanoids

It is a chemistry of volatile oils found in phenols or phenolic ether volatile oils

• C6

• C3

Phenylpropanoids contain the __ phenyl ring with an attached _ propane side chain

• Cinnamic acid

• Para-hydroxycinnamic

• para-coumaric acid

Precursor of Phenylpropanoids