ESSENTIAL OIL of MUGWORT
The constituents of the Essential Oil:
IsoBornyl IsoButyrate (38%),
Chrysanthenyl Acetate (24%),
1,8-Cineole (aka Eucalyptol) (18%),
α-Thujone forms) (20%),
Germacrene D (15%),
Artemesia Ketone (8%),
Artemisia Alcohol (3%),
trans-Rose Oxide (2%),
Santolina Triene (0.6%),
Caryophyllene Alcohol (0.5%),
Artemisia Triene (0.2%),
Caryophyllene Oxide (0.1%),
Pentyl Butyrate (0.1%),
Dozens of other components at still lower concentrations have been observed. It is reasonable to expect that, being volatile to varying degrees, almost all of the above will have an aroma of some sort, pleasant or foul.
These are the maximum concentrations found; the minimum can be, and often is, anything from the maximum all the way down to zero especially for the more volatile and lighter aromatic compounds. This is why they do not add up to 100%. The exact composition often has more to do with the soil, the environment, pests and pathogens and the weather than much else. The proportions also vary with season: the monoterpenes are highest when Mugwort is flowering, whilst the sesquiterpenes (with 50% more atoms and hence less volatile) are at their highest concentrations before flowering.
The constituents shown below are just a small selection of the known terpenoids often found within the essential oil of Mugwort.
Artemisia Triene, C10H15 and
Artemisia Alcohol C10H18O,
Artemisia Ketone C10H16O, and
Santolina Triene (sometimes mis-spelled 'Santalina Triene') C10H15 all have ten carbon atoms, although with differing arrangements. Both Artemisia Triene, Artemisia Alcohol and Artemisia Ketone have the same carbon skeleton, but differing arrangements of the position of some double-bonds between the carbon atoms. Santolina Triene has a shorter carbon backbone than either of the other three. Artemisia Triene and Santolina Triene are both monoterpenes and in particular are alkatrienes, the other two are monoterpenoids.
Santolina is a genus of plants in the Chamomile tribe which is in the Asteraceae family in which SantolinaTriene was first found.
IsoBornyl IsoButyrate is used in the perfume industry. It has a Camphor skeleton of a 6-membered carbon ring with a diagonal carbon bridge. It possesses a 'balsamic' or pine-needle odour.
Spathuthenol and α-
Gurjurene are tricyclic sesquiterpenenoids of the Aromadendrane type. They possess a fused propane ring. Spathuthenol is an alcohol which is also found in
Tarragon (Artemisia dracunculus),
Perforate St John's-wort (
Clary Sage (Salvia sclarea) several species of Nepeta including
Catnip (Nepeta cataria) and in several other Genera. Gurjunene is similar but is wholy hydrocarbon and with a double-bond in the 5-membered ring.
Rose Oxide has two isomers, trans- and cis- Rose Oxide. Both are found in Roses but only the cis- isomer is responsible for the rose aroma; it has an odour threshold of just 0.5ppb so very little needs to be in the air to be detectable by human nose. It too is used by the perfume industry, but is synthesised for this purpose. At its heart is a pyran ring with a heterocyclic oxygen atom.