Page 183 - PG 504-theoretical notes-phyto-1-2024-2025..

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Volatile Oils (Essential oils)

Volatile oil is a water immiscible complex mixture of low molecular weight, volatile
constituents of different classes of organic compounds including hydrocarbons and oxygenated
organic compounds. They are termed ethereal or essential oils (represent the essences of the
plants).

N.B. Only a few of the volatile oils poss a single component in a high percetange (e.g. volatile
oil of mustard yeild not less than 93% of allylisothiocyanate).the volatile oils.

Definitions:

Volatile oil is a water immiscible complex mixture of low molecular weight, volatile
constituents of different classes of organic compounds including hydrocarbons and oxygenated
organic compounds. They are termed ethereal or essential oils (represent the essences of the
plants). N.B. Only a few of the volatile oils posses a single component in a high percetange
(e.g. volatile oil of mustard yeild not less than 93% of allylisothiocyanate).

Volatile oils are characterized by:

1- Capable of volatilization.

2- Can be distilled from their natural sources.

3- Do not consist of glyceryl esters of fatty acids.
4- Cannot be saponified with alkalis.

5- Do not become rancid.

6- Oxidized and resinify when exposed to light or air.

7- Do not leave permanent stains on filter paper.

Fixed Oil: is non volatile glyceryl ester of fatty acid.

Mineral oil: high molecular weight

hydrocarbons obtained from petroleum oil (as paraffin oil)

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