Non-volatile components of the essential oil secretory cavities of Eucalyptus leaves: discovery of two glucose monoterpene esters, cuniloside B and froggattiside A.
The essential oils extracted from the embedded foliar secretory cavities of many Eucalyptus species are of economic value as pharmaceuticals and fragrance additives. Recent studies have indicated that Eucalyptus secretory cavities may not be exclusively involved in the biosynthesis and storage of essential oils. Therefore, we selected three species upon which to perform an examination of the contents of foliar secretory cavities: Eucalyptus froggattii, E. polybractea and E. globulus. This paper describes the isolation and structural characterization of two non-volatile glucose monoterpene esters, which we have named cuniloside B and froggattiside A, from within the secretory cavities of these species, and shows the presence of these compounds in solvent extracts of the leaves from two other species of Eucalyptus. Both compounds were found in high proportions relative to the essential oils extracted from the leaves. We propose that many other carbohydrate monoterpene esters previously isolated from bulk leaf extracts of various Eucalyptus species may also be localized within the non-volatile fraction of foliar secretory cavities.
Goodger
Jason Q D
JQD
School of Botany, The University of Melbourne, Victoria 3010, Australia. Electronic address: jgoodger@unimelb.edu.au.
Cao
Benjamin
B
Bio21 Molecular Science and Biotechnology Institute and School of Chemistry, The University of Melbourne, Victoria 3010, Australia.
Jayadi
Inneke
I
School of Botany, The University of Melbourne, Victoria 3010, Australia.
Williams
Spencer J
SJ
Bio21 Molecular Science and Biotechnology Institute and School of Chemistry, The University of Melbourne, Victoria 3010, Australia. Electronic address: sjwill@unimelb.edu.au.
Woodrow
Ian E
IE
School of Botany, The University of Melbourne, Victoria 3010, Australia.
D000080462:Acyclic Monoterpenes; D001315:Australia; D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry / Q000302:isolation & purification; D004952:Esters; D005052:Eucalyptus / Q000737:chemistry* / Q000235:genetics; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry / Q000302:isolation & purification*; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry* / Q000302:isolation & purification*
D000080462:Acyclic Monoterpenes; D003509:Cyclohexanecarboxylic Acids; D004952:Esters; D005960:Glucosides; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; C543011:cuniloside B; C543010:froggattiside A; C417926:oleuropeic acid