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

Classification of Volatile Oil Constituents

• Hydrocarbons

• Oxygenated compounds

1- Alcohols 2- Phenols and phenolic ether 3- Aldehydes 4- Ketones

5- Esters 6- Acids 7- Oxides 8- Peroxides

• Sulfur compounds

• Sulfur and nitrogenous compounds

• Oxygenated Compounds
• Compared to H.C., oxygenated compounds are:

• stable (i.e less oxidation & less resinification)

• soluble in (dil.) alcohol

• have better & stronger odour

• Removal of the hydrocarbon fraction from the volatile oil gives “terpeneless volatile
oil” with better “odour/stability/solubility”.
Preparation of the oxygenated compounds:

1) By removal of terpene H.C. by:

• fractional distillation
• counter current chromatography
2) By formation of derivatives

• Isolation of the individual components of the oxygenated constituents:

• A single pure compound from a volatile oil is termed as “isolate” and used to enrich
another oil or for semisynthesis.

• Ex: Eugenol → an isolate of clove oil

• Ex: Cineol → an isolate of eucalyptus oil CH 2 OH

A. Acyclic alcohols Citronellol
[H] [O]
1) Citronellol

Occurrence: Rose oil and Java citronella oil. CHO

Character: colourless oily liquid, with rose-like odour.
Citronellal
Isolation:

º
-by fractional distillation (at 225 C)

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