Part 1: The Basics of Essential Oil Chemistry
structure they both contain a special kind of double bond with an
oxygen atom. For instance, experimental research suggests that
essential oils rich in menthone or carvone (i.e., Peppermint and Dill)
can be soothing to the tissues and also support digestive function.*
Although categorizing oils by functional group does not tell the entire
story of use and efficacy, it is clear that it can provide a meaningful
framework for daily usage of essential oils.
CHAPTER 3: THE FUNCTIONAL GROUPS
AND THEIR FUNCTIONS
There are more than 20 different functional groups in organic
chemistry, but there are only 8 main functional groups found in
essential oil constituents. The functional groups in essential oils are
alcohols, aldehydes, alkenes, ketones, esters, ethers, phenols, and
phenylpropenes. In this chapter, we’ll discuss the atomic structure of
each of these functional groups, their properties and potential uses,
and examples of oils and constituents that contain these functional
groups.
It is important to realize that functional groups and carbon backbones
are two separate features of aromatic compounds. This means that
a molecule can be both a monoterpene and an alcohol at the same
time. Likewise, there are molecules that are sesquiterpene alcohols,
monoterpene aldehydes, sesquiterpene ketones, etc. Every possible
combination of terpene and functional group represents its own
unique class of molecules.
In this section, generalizations are made based on chemistry to
develop a conceptual framework for grouping and categorizing oils.
There will be exceptions to these generalizations. For example, while
many alcohols have health benefits when taken internally, some are
not recommended for internal use.
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