Melaleuca Oil Profiles
This website lists detailed analyses of the leaf oils of virtually all Melaleuca species and subspecies, as at May 2013. It is designed to complement the publication ‘Melaleucas: their botany, essential oils and uses’ (ACIAR Monograph No. 156). In this publication, as well as detailed descriptions of the botany and uses of melaleucas, are listed brief descriptions of the leaf oils of the species, mentioning the more significant compounds found in the oils, but not all the components. Those detailed analyses are included on this website. Where several samples gave similar results, only a representative analysis is included here, or if there were some extreme oil compositions, those analyses are included too. (Hence, yield ranges given in the monograph may not match data in these online tables.)
Using the oil profiles
- Search by species: this includes Melaleuca synonyms (such as Callistemon species)
- Search by oil type: this displays the species dominated by particular oil compositions, including the oils of economic significance.
- Search by synonym: this displays the synonym for each species.
For each oil profile
The top of the oil profile includes:
- species name, including the subspecies or variety name, if relevant
- collection identification, if available—this may be a collector’s code, collection site or some other note identifying from where the plant material came
- ‘JB’ number—this is the sample code designated by the oil analyst
- other details specific to the sample are also sometimes included.
Notes regarding the compound list:
- compounds are listed in the order of elution, and presented as a percentage of the total oil
- mw = molecular weight
- tr = trace
- ..tent.. = the identification is tentative
- an empty cell in a row means the compound was not found in the relevant sample
- a vertical line in the percentage column means the figure above it is the sum of the two relevant compounds. (These cases occur in analyses made early in the 20 years of analysis, when the resolution of the columns was not as good as it was later on. From GC/MS analysis, it was obvious that there was more than one compound present in the peak but it was not possible to know what the percentage of each compound was.)
Beneath the table includes, where available:
- yield is given a percentage dry (D) or fresh (F) weight (of original sample)
- (Australian) Tree Seed Centre No. (national facility for source-identified seed of Australia’s trees and shrubs)
- source, being the geographical location where the sample was collected
- any other relevant information.
Further background information
The oil profiles may be of use to people interested in developing commercial productions of oil or for ‘cottage industry’ type production. It may be that the leaf oils could be used as a by-product when another part of the tree is being used commercially.
The analyses have been made over a 20-year period, as samples were collected. Some species were collected from widely spaced localities and were analysed to check if location caused any variation in the oils (it sometimes did). Hence, there can be multiple collections of the same species, however different collections are included here only if they gave significantly different oil analyses.
The oils were all obtained by steam distillation with co-hobation, mostly in an apparatus as shown on the right. Distillation times varied according to what type of oil occurred in the species but was a minimum of 3 hours for oils containing only monoterpenes, principally hydrocarbons or 1,8-cineole, and up to 15 hours for oils that contained large amounts of sesquiterpene alcohols.
The oils were analysed by both gas–liquid chromatography (GLC) and gas chromatography/mass spectrometry (GC/MS). Mostly they were analysed on polar GLC columns (DB-Wax, BP-20) but some were also analysed on a non-polar column (DB-5, BP-5). Over the years, several mass spectrometers were used: an MS12 magnetic sector mass spectrometer coupled to a Shimadzu GC6-AMP gas chromatograph; a Hewlett Packard 5890 gas chromatograph coupled to a VG Quattro quadrupole mass spectrometer; and a Shimadzu QP 5000 GC/MS system. In the oil profile tables, the components are reported in the order that they eluted from a polar GLC column.