Lesson 5.1. Introduction to Volatile Oils

Volatile oils/ ethereal oils / essences/ essential oils

formally defined as odorous principles found in various plant parts

refractive indices

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

1 = ?

Optically

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

2 = ?

specific rotation

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

3 = ?

glyceryl esters of fatty acids

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

4 = ?

very slightly soluble

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

5 = ?

resinify

General Properties of Volatile Oils

1. High ______________________

2. _______________ active

3. ___________________ is a valuable degree

4. Do not consist of ________________________

5. ______________________ in water

6. _____________ upon oxidation

6 = ?

water

General Properties of Volatile Oils

• Immiscible with ________, but soluble to impart their odor

ether, alcohol, and most organic solvents

General Properties of Volatile Oils

• Soluble in __________________________

tightly stoppered, full, amber container

General Properties of Volatile Oils

• Container should preferably be a _________________________________

Odor and Taste

General Properties of Volatile Oils

• _____________________ determined by oxygenated constituents

Eleoptene

Volatile Oil has liquid and solid components:

• hydrocarbon portion of the oil (liquid)

eucalyptol, eugenol, methyl salicylate

Volatile Oil has liquid and solid components:

• examples of eleoptene

Stearoptenes

Volatile Oil has liquid and solid components:

• oxidized, solid portions

menthol, thymol, anethole

Volatile Oil has liquid and solid components:

• example of stearoptenes

sugar solution in ethanol

QUALITY TESTING

• BP: Oils should not be tasted but only after dilution with ________________________________

hydroxylamine HCl

QUALITY TESTING

• Ketone and aldehyde content can be determined by using:

sodium bisulfite method

QUALITY TESTING

• Aldehydes furthermore can be determined using:

Specific rotation and refractive indices

QUALITY TESTING

• _________________________________ can reflect purity

Modern gas chromatography

QUALITY TESTING

• _________________________________ allows differentiation between isomers (helps in checking for purity)

terpenes

BIOSYNTHESIS:

• Most non-aromatic volatile oils (hydrocarbons, alcohols) are a.______________ and come from b.__________________________________________ pathway

a = ?

mevalonate (MVA) or methylerythritol phosphate (MEP)

BIOSYNTHESIS:

• Most non-aromatic volatile oils (hydrocarbons, alcohols) are a.______________ and come from b.__________________________________________ pathway

b = ?

Monoterpenes

BIOSYNTHESIS: (MVA or MEP)

• most common class of volatile oils

Sesquiterpenes

BIOSYNTHESIS: (MVA or MEP)

• largest class of terpenoids

Diterpenes

BIOSYNTHESIS: (MVA or MEP)

• include resin acids such as pimaric and abietic acid of pine resin (to be discussed in resins)

phenolic

BIOSYNTHESIS:

• Other volatile oils, especially those with a a._________ structure, are formed from the b.________________ pathway

a = ?

shikimic acid

BIOSYNTHESIS:

• Other volatile oils, especially those with a a._________ structure, are formed from the b.________________ pathway

b = ?

greatest

BIOSYNTHESIS

• The substance used for classification is not necessarily the one present in _____________ amount

Monoterpenes

BIOSYNTHESIS

• derived from limonene

• Cyclases determine skeletal class of the terpene

• Occur in plants as glycosides

Geranyl pyrophosphate

BIOSYNTHESIS

• trans – precursor of acyclic monoterpenes

Neryl pyrophosphate

BIOSYNTHESIS

• cis – precursor of cyclic monoterpenes

Limonene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• most widely distributed monocyclic monoterpene

Cymene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• coriander, thyme, cinnamon, myristica

Pinene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• conifer oils

Sabinene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• cardamom and lemon

Myrcene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• myrcia, lemon, myristica

Cadinene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• juniper tar

Caryophyllene

EXAMPLES OF KEY TERPENOID VOLATILE OILS

• wormwood, peppermint, cinnamon, and clove

Schizogenous/lysigenous ducts

ANATOMICAL SOURCES

• Volatile Oil Location of Rutaceae (citruses)

Schizogenous/lysigenous ducts

ANATOMICAL SOURCES

• Volatile Oil Location of Pinaceae (pines)

Oil tubes called vittae

ANATOMICAL SOURCES

• Volatile Oil Location of Apieaceae/ Umbelliferae (celery family)

Modified parenchyma

ANATOMICAL SOURCES

• Volatile Oil Location of Piperaceae (peppers)

Glandular trichomes

ANATOMICAL SOURCES

• Volatile Oil Location of Lamiaceae/Labiateae (mints)

Petals

ANATOMICAL SOURCES

• Volatile Oil Location of Rose (and many others)

Bark

ANATOMICAL SOURCES

• Volatile Oil Location of Cinnamon

Water distillation

METHODS OF OBTAINING VOLATILE OILS

• for plants not subject to injury by boiling

• ex: turpentine

Clavenger apparatus

METHODS OF OBTAINING VOLATILE OILS

• small-scale extraction using water distillation

Water and steam distillation

METHODS OF OBTAINING VOLATILE OILS

• for dried and fresh materials that may be injured by boiling

• ex: cinnamon, clove

Direct steam distillation

METHODS OF OBTAINING VOLATILE OILS

• for fresh plants, cut and placed to a metal distilling tank

• ex: mints

Distillate separates into two layers

METHODS OF OBTAINING VOLATILE OILS

• he oil is withdrawn through the upper outlet and the water from the lower outlet

• or vice-versa when the oil is heavier ex. oil of clove

Rectification

METHODS OF OBTAINING VOLATILE OILS

• second distillation in stead, which frees the oil from resinous and other impurities

• ex: pine trees

Cohobation

METHODS OF OBTAINING VOLATILE OILS

• repeated distillation

rapid

METHODS OF OBTAINING VOLATILE OILS

• Special note for Chenopodium oil: Distillation must be as a.____ as possible, as the active b._____________ gradually decomposes on boiling

a = ?

ascaridole

METHODS OF OBTAINING VOLATILE OILS

• Special note for Chenopodium oil: Distillation must be as a.____ as possible, as the active b._____________ gradually decomposes on boiling

b = ?

Enzymatic hydrolysis

METHODS OF OBTAINING VOLATILE OILS

• done to glycosides to yield odorous principles (such as mustard by myrosin)

Expression

METHODS OF OBTAINING VOLATILE OILS

• for substances that decompose under heat

• ex: lemon and orange

Ecuelle a piquer

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• puncturing the fruit rind by rolling the entire fruit

Sponge process

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• similar to ecuelle, but using the rind only

Machine Process

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• either sponge or Ecuelle after centrifuging

Enfleurage

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• placement of petals on fixed oil that absorbs the volatile oil which would then be called the pomade

• the fixed and volatile oil may then be separated by alcohol

Pneumatic method

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• similar to enfleurage but uses a current of warm air through the flowers

• the air is then passed through a spray of melted fat in which the volatile oil is absorbed

Extraction

METHODS OF OBTAINING VOLATILE OILS

Variations of Expression

• percolator, Soxhlet apparatus

• uses petroleum ether and benzene to gove a more natural odor

concrete

METHODS OF OBTAINING VOLATILE OILS

Extraction

• After solvent distillation, the resulting pure essential oil is called the a.________ (contain insoluble plant or flower waxes)

• Impurities are removed by dissolving in strong alcohol, separating the waxes by filtration, then congealing (chilling to around 20 oC) - resulting products are known as b.___________

a = ?

absolutes

METHODS OF OBTAINING VOLATILE OILS

Extraction

• After solvent distillation, the resulting pure essential oil is called the a.________ (contain insoluble plant or flower waxes)

• Impurities are removed by dissolving in strong alcohol, separating the waxes by filtration, then congealing (chilling to around 20 oC) - resulting products are known as b.___________

b = ?

Destructive Distillation

METHODS OF OBTAINING VOLATILE OILS

• uses heat without air, and the resultant mass is charcoal, with addition of methyl alcohol, acetate, and tarry liquid

• produces empyreumatic (smoky odor) oils

• used in families Pinaceae and Cupressaceae

top notes

In perfumery, volatiles can either be:

• highly volatile

lemon, clove, anise oils

In perfumery, volatiles can either be:

• top notes examples

middle notes

In perfumery, volatiles can either be:

• intermediate volatility

thyme, rose, neroli

In perfumery, volatiles can either be:

• middle notes examples

base notes

In perfumery, volatiles can either be:

• low volatility

• fixatives that give the lasting odour of perfumes

vanilla and tonka

In perfumery, volatiles can either be:

Examples of base notes

1. ____________________

2. from perpetual follicles of musk deers Moschus

3. from secretions appearing in discharging pockets of the civet cat Paradoxurus hermaphroditus,

4. from stomach of sperm whale Physeter macrocephalus upon feeding on squid or cuttlefish

1 = ?

musk

In perfumery, volatiles can either be:

Examples of base notes

1. ____________________

2. from perpetual follicles of musk deers Moschus

3. from secretions appearing in discharging pockets of the civet cat Paradoxurus hermaphroditus,

4. from stomach of sperm whale Physeter macrocephalus upon feeding on squid or cuttlefish

2 = ?

civet

In perfumery, volatiles can either be:

Examples of base notes

1. ____________________

2. from perpetual follicles of musk deers Moschus

3. from secretions appearing in discharging pockets of the civet cat Paradoxurus hermaphroditus,

4. from stomach of sperm whale Physeter macrocephalus upon feeding on squid or cuttlefish

3 = ?

ambergris

In perfumery, volatiles can either be:

Examples of base notes

1. ____________________

2. from perpetual follicles of musk deers Moschus

3. from secretions appearing in discharging pockets of the civet cat Paradoxurus hermaphroditus,

4. from stomach of sperm whale Physeter macrocephalus upon feeding on squid or cuttlefish

4 = ?

Insect repellants

USES OF VOLATILE OILS:

• prevent destruction of plant

Insect attractant

USES OF VOLATILE OILS:

• aid in fertilization

inhalations, gargles/mouthwashes, transdermally

USES OF VOLATILE OILS:

• administered as _________________________________

antiseptic

USES OF VOLATILE OILS:

• High phenol content oils can be used as _____________________

Antimicrobial, antiulcer, cardiovascular

USES OF VOLATILE OILS:

• _________________________________ properties

spices and condiments (anise, clove, nutmeg)

USES OF VOLATILE OILS:

• Powdered and employed as _________________________________

Carminative and antispasmodic

USES OF VOLATILE OILS:

• found in eucalyptus, wintergreen

ETC

USES OF VOLATILE OILS:

• Many interfere with the ____ in a variety of bacteria