- Essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants.
- They are usually lipophilic (literally: oil-loving) compounds that usually are not miscible with water. Also, they can be diluted in solvents like pure ethanol and polyethylene glycol.
- They are also known as volatile oils, ethereal oils or aetherole.
- They carry a distinctive scent or essence of the plant.
- They are used in perfumes, cosmetics, soaps, lotions and other products. For flavoring food and drinks and for adding scents to incense and household cleaning products.
- It is used medicinally for skin treatments to remedies for cancer.
- Essential oils are derived from various sections of plants barriers – all spices, juniper etc.
|Leaves||Basil, cinnamon, lemon grass|
|Flowers||Cannabis, clove, chamomile, lavender|
- Families particularly rich in essential oils includes Compositae (Sunflower), Labiataceae/Lamiaceae (mint), Oleaceae, Myrtaceae (eucalyptus all sp.) etc.
- Some best essential oils are lemon oil, cinnamon oil, clary sage, lemongrass oil, lavender oil, tea tree oil, eucalyptus.
Classification of Essential Oils
Essential oils can be divided into 2 groups-
- They contain 10 Carbon atoms.
- They are built up of 2 isoprene units.
- They are open ring.
- Simple monoterpenes are widely spread.
- They tend to occur as component of majority of essential oils.
Monoterpenes can be further divided into 2 groups. They are:
1. Monocyclic Monoterpenes: e.g. Limnonene, menthol, thymol etc. Menthol is a chief monoterpene compound and source of pipermint oil.
2. Bicyclic Monoterpenes: e.g. α-pinene, β-pinene, camphor etc.
- They contain 15 Carbon atoms.
- They consist of 3 isoprene units.
According to the basic Carbon skeleton, they can be further divided into 3 groups. They are-
- Acyclic sequiterpenes
- Monocyclic sequiterpenes (Abscisic Acid)
- Bicyclic sequiterpenes
References & Other Links
- Class lecture of Rifat Samad Mam, Assistant Professor, Department of Botany, University of Dhaka
Tubaia Zannat Juthi, B.S. (Hons), Department of Botany, University of Dhaka