Terpenes are ubiquitous, but it is interesting to observe how it is possible - for certain sources - to obtain products in which they are present in majority quantities; these are mainly terpene blends, or more simply ESSENTIAL OILS.
Many sources provide us with essential oils, but it must be pointed out that all these oils are not contained within the drug or within the plant; it cannot be said, in fact, that within a secretion structure there is, for example, the essential oil of rosemary; instead there will be the terpenes, which only if extracted in a certain way will constitute the essential oil of rosemary. Inside a secretion structure there are therefore other molecules and very probably also terpenic compounds with a high molecular weight; therefore, if the correct extraction technique is not adopted, the quality of the essential oil is invalidated.
It is more correct to say that the essential oil is a predominantly terpenic mixture that is obtained with certain extraction methods. If the extraction method used is different from the correct one, all the terpenes of the essential oil will be extracted, but also more.
The sources of essential oils are numerous and diversified:
It is important to observe that from the same source it is possible to obtain different drugs, which can also give different essential oils. Of the "bitter orange, for example, the peel of the fruits, the flowers and even the leaves are used. The fruits are extracted in a certain way and give a type of essential oil called" essential oil of bitter orange "; the flowers are extracted with a different technique, and give another type of essential oil, called "neroli", the leaves, finally, recognize a further extraction method and further will also be the "essential oil, called" petit-grain ".
Therefore, different essential oils can be obtained from the same source which are located in different structures or organs. Generally, essential oils are predominantly terpenic blends, obtained with particular extraction methods, which make these blends almost exclusively made up of mono and sesquiterpenes. These molecules are generally contained in secretory structures: external (hairs, scales, emergencies) or internal (schizolysis pockets, resiniferous or laticiferous canals and vacuoles). Essential oil is obtained from fresh sources, never dried; it is therefore one of the few cases in which a proper drug is used in the fresh state.
Other articles on "Essential Oil Drugs"
- The terpenes
- Pharmacognosy
- Plants rich in essential oils