Leaf Essential Oils of the Australian Species of Gyrocarpus and Hernandia(Hernandiaceae)

Abstract

The leaf oils of the three species of Hernandia occurring in Australia were investigated. All gave oil in low (trace-0.05%) yields which were almost entirely sesquiterpenic in content. Hernandia albiflora gave oils in which bicydogermacrene (trace -19%), β-caryophyllene (5-9%), caryophyllene oxide (7-18%) and globulol (4-6%) were the principal components. H. bivalvis gave oils in which bicyclogermacrene (20-30%), β-caryophyllene (4-13%), α-copaene (11-13%) and germacrene D (7-12%) were the principal components. The oils of H. nymphaeifolia from Australia and Fiji contained β-caryophyllene (11-44%), α-humulene (14-17%) and caryophyllene oxide (5-20%) as principal components. Gyrocarpus americanus subsp. americanus, from Australia, gave a leaf oil (in 0.2-0.7% yield) whose composition was more variable. In some oils the α-pinene and β-pinene content accounted for 40% while in other oils sesquiterpenes accounted for the majority of the oil, with germacrene D (31%) being the principal component. G. americanus subsp. sphenopterus gave an oil in 0.2% yield in which sesquiterpenes were the major components.

Key Word Index:

• Hernandia albiflora
• Hernandia bivalves
• Hernandia nymphaeifolia
• Gyrocarpus americanus subsp
• americanus
• Gyrocarpus americanus subsp
• sphenopterus
• Hernandiaceae
• essential oil composition
• β-caryophyllene
• germacrene D
• bicydogermacrene
• α-copaene
• α-humulene
• caryophyllene oxide
• α-pinene
• β-pinene