Leaf essential oils of the Australian species of Gyrocarpus and Hernandia (Hernandiaceae)

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 e ntirely sesquiterpenic in content. Hernandia albiflora gave oils in which b icyclogermacrene (trace -19%), beta -caryophyllene (5-9%), caryophyllene ox ide (7-18%,) and globulol (4-6%) were the principal components. H. bivalvis is gave oils in which bicyclogermacrene (20-30%), beta -caryophyllene (4-13 %), alpha -copaene (11-13%) and germacrene D (7-12%) were the principal com ponents. The oils of H. nymphaeifolia from Australia and Fiji contained P-c aryophyllene (17-44%), alpha -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 alpha -pinene and beta -pinene content accounted for 40%, while in other oils sesquiterpenes accounted for the majority of t he oil, with germacrene D (31%) being the principal component. G. americanu s subsp. sphenopterus gave an oil in 0.2% yield in which sesquiterpenes wer e the major components.