Classification of volatile oils

Essential oil components are divided into terpenoids and non-terpenoids.
1. Non-terpenoids. This group contains short-chain aliphatic substances, aromatic substances, nitrogenated substances, and substances with sulphur. They are less important than terpenoids in terms of uses and applications.
2. Terpenoids. These are more important commercially and in terms of their properties.

According to their function group they can be:
• Alcohols (menthol, bisabolol) and phenols (timol, carvacrol)
• Aldehydes (geranial, citral) and ketones (camphor, thuyone)
• Esters (bornile acetate, linalile acetate, methyl salicilate, anti-inflammatory compound similar to aspirin)
• Ethers (1.8 - cineol) and peroxides (ascaridol)
• Hydrocarbons (limonene, pinene ? and ?)









Compound
Functional Group Structure of Functional Group Example Properties
Alcohol
Menthol, geraniol Anti-microbe, antiseptic, tonic
Aldehyde
Citral, citronelal
sedative, antiviral

Ketone Camphor, tuyona
regenerator cellular, neurotoxic
Ester Methyl salicilate Spasmodic, sedative, antifungal
Ethers Cineol, ascaridol Expectorant, stimulant
Phenolic ether Ring--- O--C Safrol, anetol, miristicine
diuretic, carminative, expectorant
Phenol Timol, eugenol, carvacrol Antimicrobes Irritant Stimulant (immunological)
Hydrocarbons Only contain C and H Pinene, limonene Stimulant, Antiviral, antitumoral