The leaf essential oils of the Australian species of Rhodamnia (Myrtaceae)

Abstract

The essential oils of the 17 Australian members of the genus Rhodamnia have been determined. R. dumicola, R. pauciovulata, R. rubescens and R.sp. (McIlwraith Range, L. J.Webb + 9527) contained relatively large amounts of α-pinene. R. australis, R. blairiana, R. costata, R. dumicola, one chemotype of R. argentea, R. whiteana and R. sp. (Cape York, L. S. Smith 12538) contained significant amounts of α-, β-, and γ-eudesmol as well as significant amounts of α- and β-pinene. R. glabrescens, another chemotype of R. argentea, R. sessiliflora, and R. spongiosa contained as principal components the sesquiterpenes β-caryophyllene, globulol, viridiflorol and spathulenol. R. maideniana and R. sp. (Calliope, N. Gibson 1335) contained significant amounts of the previously mentioned sesquiterpenes as well as five as yet unidentified oxygenated sesquiterpenes. One notable point about the essential oils of all the species of Rhodamnia examined was the almost complete absence of 1,8-cineole. In all the samples examined it was never present at levels greater than 0.1%. The oil yield on the whole was at a trace to low in most species, the highest being approximately 1% in R. whiteana and R. sp. (Callipe, N. Gibson 1335).