Volatile Oils and Waxes

What are volatile oils, and what are they also known as?

-Aromatic conc compound of plant(vegetable) origin that rapidly evaporates when exposed to air at ordinary room temp

or

-complex mixtures consisting of volatile principles contained in plants, which may be modified during preparation

- they are also known as essential oils.

What is the origin and usual location of official volatile oils in plants and exception

-vegetable origin and normally

-pre-exist in plants, stored in specialized secretory tissues such as oil cells in Citrus peels and oil ducts in umbelliferous fruits

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Oil of bitter almond and mustard oil, which is formed through the hydrolysis of glycosides rather than existing as a preformed volatile oil in the plant.

What are the proposed biological functions of volatile oils in plants?

protection against predators and attract pollinators.

What specialized secretory structures are responsible for the localization of volatile oils in different plant families?

Plant Family	Secretory Structure
Zingiberaceae	Oil cells
Lamiaceae	Glandular trichomes
Myrtaceae	Secretory cavities
Rutaceae	Secretory cavities
Apiaceae	Secretory canals
Asteraceae	Secretory canals

What are the main physical properties of volatile oils

-They are almost entirely volatile without decomposition;

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-Most have a density below 1 g/mL, except cinnamon and clove oils, which are heavier

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-they are soluble non -polar organic solvents ie: ether, chloroform and alcohol but only slightly soluble in water

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-Oxidize and resinify on exposure to air causing their colour to become darker and their odour to change slightly

How can volatile oils be distinguished from fixed oils using a paper stain?

Volatile oils produce a temporary translucent stain on paper that disappears as the oil evaporates, unlike the persistent greasy stain associated with fixed oils.

Classes of volatile oils based on biosynthetic origin

i. Terpene derivatives

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ii. Aromatic compounds

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iii. Miscellaneous Origin

terpenes or terpenoid

-terpenes or terpenoid

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Terpenes are hydrocarbons and terpenoids are terpene derivatives containing an additional functional group

Features of terpenes and terpenoids

-Terpenes, or terpenoids, are the largest group of secondary products (metabolites)

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-formed from acetyl CoA or glycolytic intermediates

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-Monoterpenes and sesquiterpenes are commonly present in volatile oils because of their relatively low molecular weights (Terpenoids)

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-Terpenoids may occur as oxygenated derivatives, e.g. alcohols, aldehydes, ketones, phenols, oxides & esters

responsible for the odour; they are slightly soluble in water and more soluble in alcohol, accounting for the characteristic odour and taste of rose water and orange water.

What is the general chemical composition of volatile oils?

They are complex mixtures of

-hydrocarbons and oxygenated compounds

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-monoterpenes(2 isoprene units)

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-sesquiterpenes (3 isoprene)

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-phenylpropane derivatives.

How are terpenes classified according to their number of carbon atoms and isoprene units?

-Made up of 5 C isoprene units

-Monoterpenes: 10 carbons (2 isoprene units);

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-sesquiterpenes: 15 carbons (3 units);

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-diterpenes: 20 carbons (4 units);

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- triterpenes: 30 carbons;( 6 units)

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-tetraterpenes: 40 carbons;(8)

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larger compounds include polyterpenoids.

How can volatile oil constituents be classified into terpene-derived and aromatic compounds, and what is an example of an aromatic compound?

Terpene-derived constituents include monoterpenes and sesquiterpenes, while aromatic compounds include benzene derivatives; vanillin is an example of an aromatic compound.

EXAMPLES OF VOLATILE OILS (TERPENES)

- LIMONENE

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-MENTHOL

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-BORNEOL

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-SESQUITERPENES

TABLE

Compound / Class	Structural & Functional Classification	Occurrence / Source	Key Uses & Applications
i. Limonene	• Structural: Monocyclic terpene • Functional: Unsaturated hydrocarbon	Citrus fruit peels and other plants	• Medical/Health: Promote weight loss, prevent/treat cancer, treat bronchitis. • Food & Pharma: Flavoring in foods/beverages/gum; skin-penetration enhancer in medicinal ointments/creams. • Manufacturing: Fragrance, cleaner/solvent, ingredient in water-free hand cleansers.
ii. Menthol	• Structural: Monocyclic with a hydroxyl group • Functional: Alcohol	Peppermint oil (Mentha piperita)	• Topical/Therapeutic: Ointments and pain balms (cooling effect at low concentrations). • Oral & Respiratory: Oral hygiene, lozenges, and syrups. • Antimicrobial: Increases shelf life of edible substances. • Cosmetics: Colognes, deodorants, soaps. • Peppermint Oil Uses: IBS, indigestion, heartburn, nausea, vomiting, morning sickness, GI/bile duct cramps, diarrhea, small intestine bacterial overgrowth, gas, colds, coughs, mouth/throat inflammation, sinus/respiratory infections, liver/gallbladder problems, and mosquito repellent.
iii. Borneol (Cinnamon Oil context)	• Functional Classification: (Not explicitly categorized in notes, sourced via cinnamon bark oi)	Cinnamon bark	• Manufacturing: Small amounts in toothpaste, mouthwashes, gargles, lotions, liniments, soaps, detergents, pharmaceuticals, and cosmetics. • Foods: Spice and flavoring agent in beverages. • Medicinal/Traditional: GI upset, diarrhea, gas, appetite stimulation, bacterial/parasitic infections, menstrual cramps, cold/flu, and topical application for premature ejaculation (multi-ingredient prep).
iv. Sesquiterpenes	• Contains 3 isoprene units • Acyclic: e.g., Farnesol • Monocyclic: e.g., Bisabolol • Bicyclic: e.g., Chamazulene (Chamomile)	Chamomile oil (Chamazulene)	• Topical: Skin and mucous membrane inflammations and skin diseases • Respiratory/Inhalation: Respiratory tract inflammations or irritations. • Baths/Irrigation: used in baths as irrigation for anogenital inflammation • Internal: GI spasms and inflammatory diseases (note: clinical trial support is limited). • General: Anti-inflammatory agent.
B. Aromatic Compounds (Phenols & Phenol Esters)	• Many are phenols or phenol esters • Example: Vanillin	Natural aromatic sources	• Pharmacological: -- -Anticonvulsants (prevent/reduce seizures), -antimutagenic agents: reduce the frequency of mutations -antioxidants (retard oxidation and counteract damage in animal tissues). • Industry: Flavoring agent in the food industry.

4 Main types of volatile oils(table docs)

Concretes, pomades, resinoids and absolutes. (CRAP)

Extract Type	Source Material	Extraction Method & Process	Composition & Examples	Key Characteristics & Uses
Concretes	Raw materials of vegetable origin (bark, flowers, leaves, roots, etc.)	Extracted using hydrocarbon (HC) solvents instead of distillation or expression. Necessary when essential oils are adversely affected by heat/steam (e.g., jasmine).	• ~50% wax and 50% essential oil (e.g., jasmine) • Ylang ylang concrete volatile contains 80% essential oil and 20% wax.	• Produces a more true-to-nature fragrance. • More stable and concentrated than pure essential oils.
Pomades	Flowers containing volatile oils	Enfleurage (hot or cold): Fresh cut flowers are laid individually on a glass plate coated with odorless fat (chassis) until saturated. The fat is renewed with fresh flowers, and the fragrance-saturated fat (pomade) may be treated with alcohol to extract the oil.	Produced from flowers to capture volatile oils so perfume can be made long after they are cut.	Enables the extraction of delicate floral oils that cannot withstand harsher processing methods.
Resinoids	Natural resinous material (dried material)	Extracted with a non-aqueous solvent, such as petroleum ether or hexane.	Examples: • Balsams: Peru balsam or benzoin • Resins: Amber or mastic • Oleoresin: Copaiba balsam and turpentine • Oleogum resins: Frankincense and myrrh	• Viscous liquids, semi-solid, or solid. • Usually a homogeneous mass of non-crystalline character. • Used in perfumery as fixatives to prolong a fragrance's effect.
Absolutes	Derived from a concrete, pomade, or resinoid	Alcoholic extraction (which may be repeated). The ethanol solution is cooled & filtered to eliminate waxes, and the ethanol is removed by distillation.	Obtained from intermediate aromatic extracts (concretes, pomades, or resinoids).	Usually highly concentrated viscous liquids.

What are the two official methods used to prepare volatile oils?

Steam distillation and expression.

What is steam distillation, and what are its three methods described in the lecture?

Steam distillation is a method of obtaining essential oils using steam

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-simple steam distillation

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- saturated steam distillation

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-hydrodiffusion.

How is simple steam distillation performed, and how is the volatile oil separated?

Plant material is immersed directly in water in a still and brought to a boil

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- the heterogeneous vapours are condensed on a cold surface

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- and the oil separates from the water based on differences in density and immiscibility.

How does saturated steam distillation differ from simple steam distillation, and what are its advantages?

The plant material does not come into direct contact with water; steam is injected through plant material placed on perforated trays

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. Advantages include

-reduced alteration of oil constituents

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- shorter processing time

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- energy conservation

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-suitability for automated operation

What is hydrodiffusion, and what are its main advantages?

Pulses of steam are passed through plant material from top to bottom at very low pressure

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Advt:

-high-quality product

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-saves time and energy.

How does microwave steam distillation under vacuum work, and what are its advantages?

Plant material is selectively heated by microwave radiation in a chamber where pressure is reduced; fresh plants require no added water. The method is fast, consumes little energy and often produces higher-quality oil than traditional steam distillation.

What is expression as a method of obtaining volatile oils?

A mechanical extraction method in which the oil is obtained by pressing or expressing the plant material, particularly suitable for citrus peels.

Solvent extraction( PRODUCTION OF

CONCRETES & RESINOIDS)

-Cut the plant material into small pieces

bruising the fresh, wilted or semi-desiccated organs, chopping herbaceous drugs, pounding roots & rhizomes or turning wood into chips or shavings

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-Mix plant material with solvent to dissolve desired constituents

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-filter to separate liquid extract from solid plant residue

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-evaporate solvent leaving extracted compound

selection of solvent

-stability

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- (chemical inertness) and safety.

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-compatibility (being a good solvent for the specific constituents)

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-Boiling point should not be so high that the solvent can be completely eliminated; nor too low, to limit losses & control cost

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-Solvents most used are – petroleum ether, hexane, propane & liquid butane

Main disadvantages

-Lack of selectivity(compatibility) many lipophilic substances may end up in the concretes & render further purification necessary

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- The toxicity of solvents → leads to the restrictive regulations regarding their use

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- Residues in the final product

What is the difference between cold and hot enfleurage?

Cold enfleurage involves diffusion of fragrant compounds into fat at room temperature, whereas hot enfleurage (digestion) involves immersing plant material in melted fat using heat.

Explain production of volatile oils using fats and oils

-takes advantage of the liposolubility of the fragrant components of plants in fats

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-Enfleurage”– the plant material is placed in contact with the surface of the fat.

- diffusion of fragrant compounds into fat at room temperature9cold diffusion)

- Immersing plant material in melted fat using heat (hot enfleurage)

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-final product is known as a floral pomade

PNEUMATIC METHOD (USING OILS & FATS)

-passage of a current of hot air through the flowers

-air then saturated with suspended volatile oil

-passed through a spray of melted fat in which the volatile oil is absorbed.

How does supercritical gas extraction work, and which gas is mainly used?

Beyond its critical point, a fluid has the density of a liquid(can dissolve substances) and viscosity of a gas(easy flow) therefore a supercritical liquid, allowing it to diffuse through solids and act as a solvent; carbon dioxide is the main gas used.

What are the advantages and disadvantages of supercritical carbon dioxide extraction?

Advantages: non-toxic, non-flammable, chemically inert, selective, inexpensive, readily available, easy to eliminate and capable of producing extracts close to the natural composition.

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-Disadvantage: high initial investment and technical constraints.

USES of SUPERCRITICAL GASSES method

-developed to decaffeinate coffees; remove nicotine from tobacco

-Prepare spice extracts (ginger, paprika

- Plant oils

- Specific flavours (black tea, oak wood)

TREATMENTS OF THE OILS

decolourize, neutralize or rectify the oils obtained.

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-Steam jet under vacuum

Allows for the elimination of smelly or irritating desired “profile”. ii. products, and to obtain a final product of desired profile

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-permits a good separation of the essential oil from non-volatile lipophilic compounds.

What factors cause variations in the composition and quality of volatile oils?

The occurrence of chemotypes, the vegetative cycle, environmental factors and the method of preparation.

What are chemotypes, and how can they affect volatile oil composition?

Chemotypes are chemical varieties or breeds within a plant species that contain different types and proportions of volatile oil constituents; for example, Thymus vulgaris has seven different chemotypes.

How does the vegetative cycle affect volatile oil composition?

The proportions of oil constituents can change throughout plant development; examples include fennel, carrot and coriander, in which linalool is higher in ripe fruit than unripe fruit, and peppermint, which is also greatly affected.

Which environmental and cultivation factors influence volatile oil content and quality?

Temperature, humidity, duration of daylight, radiation, wind patterns, fertilization and watering practices influence volatile oil content, yield and quality

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-Fertilization and the amounts of N, P and K have been studied for various species

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-watering regiment also plays an important role.

How can the method of preparation alter the original composition of volatile oils?

During steam distillation, water, acidity and temperature may cause ester hydrolysis, rearrangements, isomerization, racemization, oxidation and other reactions, producing an oil composition different from that originally present in the plant.

What are the general pharmaceutical and commercial uses of volatile oils?

Therapeutic agents, flavouring agents, perfumery ingredients, starting materials for synthesizing other compounds and aromatherapy.

How can volatile oils act as antiseptics and preservatives, and which crude drug is an example?

High phenol content contributes to antiseptic activity, as in thyme oil; volatile oils can also act as preservatives by interfering with bacterial respiration.

Which volatile oils or crude drugs are associated with antispasmodic activity?

Ginger, lemon balm, rosemary, peppermint, chamomile, fennel and caraway.

What are the main constituents, actions and uses of ginger as a volatile-oil-containing crude drug?

Ginger (Zingiber officinale) is the peeled or unpeeled rhizome of a Zingiberaceae plant. Its volatile oil (1–2%) contains camphene, cineole, citral and borneol. Actions include carminative, stimulant, antiemetic, anti-inflammatory, antibacterial and antifungal activity; uses include motion sickness and morning sickness.

What are the source, part used and volatile-oil content of cardamom?

Cardamom (Elettaria cardamomum, Zingiberaceae) consists of dried, nearly ripe fruits; the seeds are the parts used and should remain inside the fruit until needed to prevent volatile-oil loss. It contains 2.8–6.2% volatile oil.

What are the main chemical constituents of cardamom apart from its volatile oil?

Abundant starch (up to 50%), fixed oil (1–10%) and calcium oxalate.

What is cinnamon as a crude drug, and what are its main constituents and uses?

Cinnamon (Cinnamomum zeylanicum, Lauraceae) is the dried bark. It contains at least 1.2% volatile oil, phlobaphenes, mucilage, calcium oxalate and starch. The bark is used as a flavouring agent and mild astringent; its oil is carminative and germicidal.

What is lemon peel as a crude drug, and what are its main constituents and uses?

Lemon peel (Limonis Cortex) is obtained from Citrus limon (Rutaceae). It should contain at least 2.5% volatile oil, vitamin C, hesperidin, mucilage and calcium oxalate. It is used for flavouring and perfumery.

What is clove as a crude drug, and which constituents are mainly responsible for its volatile-oil composition?

Cloves are the dried flower buds of Syzygium aromaticum (Myrtaceae). They contain 14–21% volatile oil, mainly eugenol and isoeugenol, as well as sitosterol, stigmasterol, campesterol, tannins, triterpene acids and esters, and glycosides.

What are the main uses of clove oil, and how should it be stored?

Clove oil is used as an antiseptic, aromatic, stimulant and flavouring agent. It should be stored in a well-fitted airtight container protected from light and heat.

What is eucalyptus leaf as a crude drug, and what are its main medicinal uses?

Eucalyptus leaf consists of the whole or cut dried leaves of older branches of Eucalyptus globulus (Myrtaceae). It contains at least 2% volatile oil and is used to alleviate symptoms of nasopharyngeal infections, treat coughs and act as a decongestant.

How is medicinal eucalyptus oil obtained, and what determines whether the oil is suitable for medicinal use?

It is obtained by distilling fresh leaves of suitable Eucalyptus species and rectifying the oil. Medicinal suitability requires high cineole content and low amounts of phellandrene and aldehydes.

What are the main characteristics and constituents of eucalyptus oil?

It is a colourless or pale-yellow liquid with an aromatic, camphoraceous odour and a pungent, camphoraceous taste followed by a cooling sensation; it contains at least 70% volatile oil constituents, mainly cineole.

What is peppermint as a crude drug, and how is peppermint oil prepared?

Peppermint is the dried leaves of Mentha piperita (Lamiaceae), containing at least 1.2% volatile oil. Peppermint oil is obtained by steam distillation of the flowering tops.

What are the main chemical constituents and required composition of peppermint oil?

Menthol, menthone, isomenthone, menthyl acetate, limonene, cineole, menthofuran and pulegone. The oil should contain at least 44% menthol, 15–32% menthone and 4.5–10% menthyl acetate.

What are the main uses of peppermint herb and peppermint oil?

Peppermint herb is carminative; peppermint oil has antibacterial, cooling and carminative properties.

What are volatile-oil-containing crude drugs, and how do their plant parts differ?

Examples include ginger (rhizome), cardamom (fruit/seeds), cinnamon (bark), lemon (peel), nutmeg (seed kernel), clove (flower buds), eucalyptus (leaves) and peppermint (leaves).

Waxes

class of chemical compounds that are plastic in nature (malleable) near ambient temperatures. They are also a type of lipid.

physical properties

-Melt above 45 °C (113 °F) to give a low viscosity liquid

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-insoluble in water

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-Soluble in organic, nonpolar solvents

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-organic compounds

chemical properties

-Waxes are organic lipid compounds ;long alkyl

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-Natural waxes are typically esters of fatty acids and long-chain alcohols

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- while synthetic waxes are long-chain hydrocarbons lacking functional groups.

What are the main differences between plant-derived and animal-derived waxes?

Plant waxes occur mainly on plant surfaces and contain characteristic mixtures of unesterified hydrocarbons

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- animal waxes typically consist of wax esters derived from various carboxylic acids and fatty alcohols.

What factors influence the composition and melting properties of naturally produced waxes?

- species and geographical location of the organism.

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- Because natural waxes are mixtures, they are generally softer and melt at lower temperatures than their pure individual components.

What is the biological function of waxes on plant surfaces?

Plants secrete waxes on their outer surfaces to control evaporation and maintain hydration, particularly in warm climates.

What is carnauba wax, where is it obtained from, and what is its major constituent?

Carnauba wax is a hard plant wax obtained from the leaves of the Brazilian palm Copernicia prunifera (also identified in the lecture as Copernicia cerifera); it contains the ester myricyl cerotate.

How is carnauba wax collected and prepared, and what are its main uses?

New or immature palm leaves are collected and allowed to dry; the wax is then removed by beating. It is used primarily in car polishes and shoe polish.

What is candelilla wax, and what is its botanical source and commercial importance?

Candelilla wax is a vegetable wax obtained from Euphorbia antisyphyllitica (Euphorbiaceae), native to the Chihuahuan Desert in Mexico and southern Texas. It is often substituted for carnauba wax.

What is jojoba wax, where is it obtained from, and what are its main uses?

Jojoba wax is obtained from the seeds of Simmondsia chinensis (Simmondsiaceae), native to the southwestern United States and Mexico. The seeds contain a liquid wax used as a lubricant, while jojoba oil is widely used in cosmetics.

What are sugarcane wax and bayberry wax, and how are they obtained or used?

Sugarcane wax is a by-product of the sugar industry and is used for many of the same purposes as carnauba wax, although it is considered inferior in quality. Bayberry wax is obtained from the fruits of Myrica species; it was melted off to make candles, which are still used for their pleasant odour.

What is beeswax, and what is its major chemical constituent and melting point?

Beeswax is an animal wax secreted by bees and used in constructing honeycombs. Its major constituent is myricyl palmitate, and its melting point is approximately 62–65°C.

What are spermaceti and lanolin, and what are their principal chemical characteristics?

Spermaceti occurs in the head oil of the sperm whale and contains cetyl palmitate, an ester of a fatty acid and fatty alcohol. Lanolin is a wax obtained from wool and consists of sterol esters.

What are petroleum-derived waxes, and how do they differ chemically from most natural waxes?

Petroleum-derived paraffin waxes are mixtures of hydrocarbons, mainly alkanes, rather than fatty acid and fatty alcohol esters. They are obtained from petroleum and refined by vacuum distillation.

What are the main constituents of paraffin wax, and how does branching affect its properties?

Paraffin wax contains saturated normal and isoalkanes, naphthenes, and alkyl- and naphthene-substituted aromatic compounds. The degree of branching influences its physical properties.

What are the general commercial and industrial uses of waxes?

They are used in shoe and wood polishes, mascara, lipstick, carbon paper, candles, cosmetics, food coatings, cheese wrapping, chewing gum, waterproofing and non-stick coatings.

How are waxes used in paints, inks and plastic formulations?

They provide matting effects and wear resistance in paints; polyethylene waxes are added to inks as dispersions to reduce friction; polyethylene and polypropylene waxes are used in colourant formulations for plastics.

What are release agents and slip agents, and how are waxes used in these applications?

Release agents prevent materials from bonding to surfaces, while slip agents reduce friction between surfaces. Waxes are used in both applications and can also provide corrosion resistance.