1. Chemistry Myths and Misunderstandings
Who am I and why am I here?
Dr. Sue Clarke i

2. Introduction
In the 1980s I couldn't find a suitable book on essential oil chemistry so had to write my own.

3. A Lightning Tour Background to Scientific Approach The Chemistry
How Do We Make Decisions ?
Suffering from Information Overload ?
Getting Things Into Perspective
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4. Science
A systematic study of nature and behaviour of materials and the physical universe based on observation, experiment and measurement.
Evidence based knowledge
Science, especially chemistry, underpins the fundamental ideas and issues important for aromatherapy
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5. Science: Risk versus Benefit
Are we, and society in general, risk averse?
Regulations, Guidance and Safeguards –
Health & Safety, COSHH, IFRA. RIFM, MHRA
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7. Science: NATURAL SUBSTANCES versus CHEMICALS
People say the strangest things …
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8. Science: CAM versus MAINSTREAM MEDICINE
The importance of the House of Lords Science and Technology report on CAM in 2000 and it's implications
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9. Overlap and mutual support What is a natural product ?
Science: Issues
Are risk v benefit, natural v chemical and CAM v mainstream medicine polarised views ?
Overlap and mutual support
What is a natural product ?
Do you agree with the definition of an essential oil as :
The totally volatile product extracted by a physical process from a single plant species that has an odour and composition characteristic of an essential oil from that species.?
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10. Chemistry
Chemistry is a vast subject that takes many years of study building up on underpinning knowledge.
Using IFPA syllabus will give you some background.
The molecules found in aromatherapy are part of the branch of chemistry called ORGANIC CHEMISTRY.
This is the chemistry of Carbon.
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12. Chemistry
Molecules found in essential oils can be CLASSIFIED in a number of ways. The most commonly used is based on the structures of the molecules based on hydrocarbons called TERPENES and their derivatives.
The basic structural unit is called isoprene. It is a monomer and 'reacts' with itself to form larger polymers.
But isoprene is not the unit in the plant that gives rise to the terpene molecules.
They form in the plant in a series of biochemical reactions called the MEVALONIC pathway which manufactures secondary metabolites.
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13. Chemistry
Isoprene
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14. 4 isoprene units give DITERPENES with up to 20 C atoms eg camphorene
Chemistry: Terpenes
2 isoprene units give MONOTERPENES with 10 C atoms eg myrcene, limonene
3 isoprene units give SESQUITERPENES with up to 15 C atoms eg farnesene,cedrene
4 isoprene units give DITERPENES with up to 20 C atoms eg camphorene
The terpenes have names ending in ENE
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15. Chemistry: Terpenoids
The TERPENOIDS are compounds derived from the hydrocarbon terpenes but have an oxygen atom bonded into their molecules. They are arranged into FUNCTIONAL GROUPS (characteristic reactive parts of molecules) such as
alcohols OH ( names ending in ol)
ketones C=O (names end in one)
aldehydes CHO (names end in al )
esters COOC (names end in ate or acetate)
Named after the terpene and the functional group eg linalool & geraniol are monoterpene alcohols
linalyl acetate is a monoterpene acetate (ester)
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16. Chemistry: Functional Groups
Important for the reactions and characteristics of compounds.
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17. Linalool
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18. Linalyl Acetate
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19. Chemistry: What’s in a Name ?
Many different and complex names for the same compound eg. C12H20O2
Systematic (IUPAC) 3,7-dimethylocta- 1,6-diene-3-yl acetate.
Trivial linalyl acetate, linalool acetate, bergamol, bergamiol, acetic acid linalool ester, linalol acetate, lynalyl acetate and another 81 recorded names.
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20. Quantitative and Qualitative GC Gas Chromatography
Chemistry: Analysis
Quantitative and Qualitative
GC Gas Chromatography
MS Mass Spectrometry
Criteria for identification and purity
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21. Chemistry: Shapes of Molecules
Key action at membrane/cell surfaces
Many theories for sense of smell but specific binding with receptors important
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23. Chemistry: The SIZE of Molecules
Larger are less soluble, less volatile, less able to pass through membranes.
The skin barrier.
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24. Chemistry: Variation in Natural Products
Due to Species of the plant
Growth conditions – soil, climate, water availability, altitude
Chemotypes
Age of plant
Part of plant used
Extraction and processing method
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25. Chemistry: Storage Conditions
Sunlight
Temperature
Storage vessels
Exposure to atmosphere
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26. How Do We Make Decisions?
Who and what can we believe ?
Lots of terminology and definition
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27. Decisions: What is an Expert?
What exactly is meant by Studies; Research; Investigations ; Trials ; Observations?
Who is carrying out the work ?
How are the results evaluated ?
Publication of work & peer reviews
Statistics
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29. Are You Suffering From Information Overload?
Choice of materials
What can you trust ?
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30. Getting Things Into Perspective
Get qualified
Follow professional guidelines
Choose your supplier carefully
Common sense
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32. Perspective Keep an open mind Embrace change and progress
Be philosophical – Socrates
Don't forget the human factor
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33. True wisdom comes to each of us when we realise how little we understand about life, ourselves and the world around us.
Socrates 469 – 399BC
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