Chemistry of essential oils

For each essential oil, descriptions are very meticulous
and they give you analysis as well as a list of up-to-date
properties and contraindications for each plant and each batch.


In this section, we will see the simplicity and magic of the chemistry of essential oils.
Let's start by introducing the subject a bit.

Extensive studies, incredibly long studies and ultimately ... not much to bite into !

The chemistry of essential oils is partial and not sufficient.
Virtually the only information that we can find so far is from Dr. Daniel 
Pénoël and Pierre Franchomme's magnificent work .
Beautiful, but it was only a start.
And nothing seems to have been done, at least in the cradle of
aromatherapeutic precision : the French world.

Victory! Some people have continued to study.
Robert Tisserand and Dr. Stewart among others: the English world took over (i.e. the Anglo-saxon world).
One should take all this material, do some further research and summarise it to implement the findings and conclusions to the true modern daily practice of aromatherapy.

This is part of the work I have devoted my life to (Mark Ivo Böhning, hello ) and I am pleased to write this text for Gedane to present  what the current knowledge is and above all what we can do of it ... in a simple way.

Plants and their magical chemistry

We will not go into all the details here (three days of classes would not even be enough) but plants are extraordinary chemical factories.

  • First, they provide the substrate for all animal life on earth: oxygen.
  • Then they can transform solar energy into chemical energy which the entire animal kingdom (including us) takes advantage of as the sole means of livelihood.
  • Moreover, they make material from air, water and light (leaves for roofs, fruits and vegetables, wood for houses and utensils, cellulose for paper, compost, oil and the list is endless) .
  • And finally they spread visual and olfactory beauty throughout the world.

We saw under "Production of essential oils"  why plants need to produce
such noble substances as essential oils.
They have been doing so for hundreds of millions of years and have gained mastery that goes far beyond any
high-tech chemistry laboratory.
And that, even for the simplest grass!
It is absolutely impossible to artificially manufacture the vast majority of molecules they produce daily, only with water, light and air.

They had to respond to the challenges of life and have done so by adapting in symbiosis.
That is ti say, peacefully. (Well, we might already have something to learn here ...)
They had to develop a system of complex and powerful language that can be understood by other plants of the same species, and different species of different kingdoms.

This language is encoded within the molecules in their essential oils.
And we are far from understanding even a tiny fraction of it.
Just a few people have an idea of ??the genius with which they communicate.
Because there is no need to try to decipher this language - far too complex for us - considering where we stand at the moment:

  • This is just about understanding what intelligence lies inside and knowing how to deduce the toxicity of some essential oils.

That's it.
No more: enough is enough and it would be huge already when you realise how little we know and understand about plants and oils.

An astonishing intelligence

Imagine the intelligence of a bush that must survive the attack of fungi able to defeat it in no time but could not keep a new generation alive if it does not let fungi live.
It must let itself be decomposed when it dies to offer loam to its offspring.
It itself lives only thanks to the fertile ground provided by its ancestors.
Ancestors who would have died if they had let these essential bacteriae live freely and transform them into compost.

It's the same challenge for a human being.

We are totally dependent on flora (including the intestinal bacterial flora), without which we could not live more than a few days or hours.
And yet, if it looses its balance even for a little while, we know the result: we can get impressive gastric flu.

The plant has developed essential oils which are rich in hundreds of different molecules.
They are thus able to:
  • Not only kill virtually any microbe on Earth (essential oils are extremely efficient anti-infectives!)
  • But also, respect the natural flora of the host in which they are given and adapt to it.

That's why we call it language: they have a conversation with the inside of the body to respect its functionning and heal it accordingly.

There are also communication
reasons to the word "language":
Plants exchange information, they litteraly "talk".

More and more teams of scientists study these phenomena and have established this fact which seems so easy but so trivial to say:
"Plants communicate with each other."

If this phenomenon is studied, it is as much for its ecological importance as for its potential economic benefits.
But that is another story.
So thank the plants for their language ! We'll just leave our physical body and chakras translate the different levels of this tongue for us.

The plants' reactions to their environment

The stroke of genius scientists in the second part of last century was to realise that:

  • Plants produce essential oils according to their different growing conditions 
  • and adapt their nomenclature accordingly.

In fact plants do not produce for the sake of producing.
They adapt to their environment:

  • depending on the ground 
  • altitude
  • moisture
  • Season
  • its neighbors
  • etc.

Plants can produce slightly or frankly different oils.
This is called chemotypes (to mimic the genotype: the genetic type, the phenotype: the visual type, the chemotype is the chemical type).

A plant that grows in India and Madagascar will not give an
identical essential oil.

Plants provide significantly different
oils, so  their chemical type is written on the bottles and in books.
For example Thyme with thymol and Thyme with linalool.
This increases significantly the safety of our use. 

Are chemotypes really accurate ?

"Chemotype" is a word we use for the classification of molecules in essential oils.
We have classified to make things clearer.
Yet, it has been commonly accepted that we consider the effects and toxicity of molecules in a family in a too homogeneous way.

It thus confers all sesquiterpenes, all ketones, all aldehydes etc., the same properties.
But would you say your parents, children, brothers, sisters, cousins, have all the exact same features and characters just because you bear the same surname? Proably not.

In fact, there are big problems with families of molecular chemotypes and we'd better forget them to be up-to-date!

  • The classification reflects only a tiny part of the molecule (the function) so that it operates through its spatial geometry (Radical + function) to trigger responses in a cell by lock and key effect.
  • Many molecules are unclassifiable, traditionally misclassified or should be classified in several categories simultaneously.
  • Within a family, characters may vary strongly from one molecule to another.
  • The stereochemistry (which changes the shape of the molecule without being always reflected in the name of it) is largely underestimated and forgotten but if two molecules are said to be identical and are mirror images of each other, it is like a pair of gloves: a right hand does not go into a left glove and vice versa. We can not always detect which half of the mirror we hae when we analyze an essential oil (menthol, camphor, carvone, limonene, etc.).

Families of  chemical chemotypes hence, say nothing and cannot predict the toxicity or properties of essential oils, but they are handy to classify molecules and cope visually with a whole list of molecules.

We'd better stick to this only and stop listing effects by chemical groups!
Saying that ketones are neurotoxic or that monoterpenes are boosters and so on, is ancestral and false ...!

Again, it was an excellent research work done in the last century but we needed some more ... which for obvious financial reasons could not be performed.
Now, we are working hard and without any funding (sponsors welcome!) to clarify data we are also working hard to gather.

It is true that these categories give an overview and they are practical. We should just not rely on them completely or predict therapeutic effects of essential oils or contra-indications and potential side effects according to them only.

now understand why we present the chemistry of essential oils without describing lapse properties of false step-families of which each member is different.

Gedane takes a big step forward in the world of aromatherapy in terms of information. Thus, the most significant molecules, the
discriminating molecules of an essential oil, and those in greater quantities are written and quantified on the bottles and also on this website. They are important to identify an essential oil, and know what to expect in terms of toxicity, dosage etc.. Then it is molecules that we need, not families. And that's what Gedane offers seamlessly.

Monoterpenes, sesquiterpenes, diterpenes, triterpenes, monoterpene alcohols, sesquiterpene and diterpene aldehydes and aromatic non-aromatic mono-ketones, diketones monoterpene, sesquiterpene, non-terpene esters, phenols, phenol-methyl ethers, oxides, peroxides, phthalides ether-oxides, ethers, lactones, furanocoumarins, pyranocoumarines, thiols, sulfides, oxides, furan, hydroxy acids, alkaloids ...

This list of families does not live down the fact that there are over 1,000 monoterpenes, over 3,000 
sesquiterpenes ... and these are just the first two families on the list!

Making it simple

There are ways to make it easier.
The good news is that this is exactly how we should deal with chemotypes : find trustworthy reference books and trust them.
For each essential oil individually.

We can no longer think we can deduct a plant's potential toxicity from a chemical analysis (especially with a limited number of molecules) and apply these conclusions on our patients, based on families that are virtually inexistant (chemotypes).

Classifying molecules by families allowed aromatherapy to become more popular, and even brought up a certain amateurism which has made us think we were sufficiently informed to evaluate essential oils' effects or toxicity.
The best specialists will say it does not work like that.
And they are right.

The whole complex process of evaluation can and has to be performed by professionals only.

The role of consumers (as well as not chemist aromatherapist) is all the more comfortable and noce !
This doesn't mean following the lead, but selecting reliable sources, authors, books and stick to it.

Why not have a list of specific essential oils you commonly use so you don't have to be afraid (or ashamed) of opening books in front of a patient before signing their prescription ?
We all do it and this proves how professional and quality-oriented we are to take their health seriously. there are hundreds of plants, different parts oils can be extracted from, various nomenclatures and variations depending on where they come from.

Let's open our books and trust the professionals and the years of research to guide us.

As Gedane requested, I gave the most recent data about each essential oil.
They ask me to control each batch for their customer's safety (and that of my dear patients as well, as they may well buy Gedane oils in pharmacies)

Let's just have fun, read each oil description, read the section about safety and cheers to your nostrils and health !

Essential Oils

Agatophylle Agatophylle leaves Ajowan Ajwain All-spice Allspice Angelica Arabian jasmine Archangel Balsam fir Basil (exotic) Bay laurel Bergamot Bigaradier feuilles Black Pepper Black pepper Black spruce Blue ginger Camphor cineol CT leaves 1,8-cineole (Madagascar) Cananga Cane Cardamom Cedar (Atlas) Celery Ceylan citronella Chamomile Chamomile (roman) Chamomile(roman) Cilanthro (leaves) Cinnamon Cinnamon (bark) Cinnamon (leaves) Cinnamon bark Cinnamon leaves Citronella Clove Clove bud Clove leaf Cochingrass Common sage Coriander Cumin Cupressus Curcuma Curry leaf Curry plant Curry tree Cuscusgrass Cypress Davana Dill East-indian Lemongrass Eucalyptus radiata Everlasting Exotic basil Fennel Fir Fir (Balsam) Fir (balsam) Flag Frankincense Frankincense (salai) Galanga Galangal Garden Angelica Garden dill Geranium Ginger Gingergrass Grapefruit Greater galanga Green Mandarin Green Pepper Green cardamom Green pepper Grey eucalyptus Helichrysum angustifolium Helichrysum italicum Holy basil Ilang-ilang Indian Basil Indian Frankincense Indian wintergreen Jamanatsi Jasmine Jasmine (arabian) Jasmine (royal) Jeera safed Jessamine Juniper berries Khus-khus Lavender Lemon Lemon (yellow) Lemongrass Limetta Macassar-oil plant Malabargrass Mandarin Mediterranean sweet lemon Mulilam Muskroot Myrrh Nard Nardin Narrow leaf eucalyptus Narrow leaved peppermint Norway pine Officinal lavender Officinal rosemary Orange Orange (sweet) Orange bergamot Orange peel Oranger amer feuilles Oregano Palmarosa Parsley Patchouli Pelargonium Pepper Peppermint Petitgrain Bigarade Pimento Pine Pine (Norway) Pomelo Ravensara Ravintsara Roman chamomile Rose geranium Rose pelargonium Rosemary Rosemary borneon Rosha grass Royal jasmine Sacred basil Sage Salai Frankincense Salvia Sambac Scotch pine Shaddock Spanish jasmine Spearmint Spearmint Spikenard Spruce Sweet cane Sweet celery Sweet fennel Sweet flag Sweet lemon Sweet lime Sweet limetta Sweet orange Tea tree Tea tree m.a. Thai galangal Thai ginger Thyme Thyme (thymol) Tropical Basil True lavender Tulsi Turmeric Turmeric (aromatica) Turmeric (longa) Valerian Vanilla Vetiver White Pepper White cumin White pepper Wild marjoram Wintergreen Yellow lemon Ylang-ylang Zanthoxylum