Essential Oils from the Leaves of Some Queensland Annonaceae

Journal of Essential Oil Research: JEOR, Mar/Apr 2004 by Brophy, Joseph, Goldsack, Robert, Forster, Paul

Abstract

The leaf oils of seven species from the family Annonaceae, growing in Queensland, Australia, have been examined. Artabotrys sp. (Claudie River B.Gray 3240) produced oil in poor yield in which unidentified oxygenated sesquiterpenes accounted for approximately 80% of the oil. Uvaria rufa gave an oil rich in sesquiterpenes, in which the principal component was [alpha]-humulene (50%), while in Uvaria concava the principal component was spathulenol (32%). Benzyl benzoate was also present (5%) in U. rufa. In Cyathostemma micranthum the principal components were caryophyllene oxide (26%), spathulenol (11%) and benzyl benzoate (4%). The oil of Mitrephora zippeliana existed in two forms in which either monoterpenes were more prominent with [alpha]-pinene (13%) and [beta]-pinene (15%) being the major components together with the sesquiterpenes caryophyllene oxide (10%), spathulenol (10%) and [beta]-caryophyllene (8%), or sesquiterpenes were prominent with [beta]-caryophyllene (18%), [alpha]-humulene (7%), [gamma]-curcumene (4%), bicyclogermacrene (4%), ar-curcumene (5%), caryophyllene oxide (3%) and spathulenol (5%) being the principal components. Goniothalamus australis presented a leaf oil that contained significant amounts of both monoand sesquiterpenes; one sample contained pinocarvone (10%) and trans-pinocarveol (17%) as the principal monoterpenes, while a second collection contained [alpha]-pinene (10-11%) as the principal component. Cananga odorata gave a leaf oil in which the major components were [beta]-caryophyllene (34-52%), sabinene (1-20%), [alpha]-humnlene (6-11%) and [alpha]-pinene (1-17%).

Key Word Index

Artabotrys sp. (Claudie River B. Gray 3240), Cananga odorata, Cyathostemma micranthum, Goniothalamus australis, Mitrephora zippeliana, Uvaria rufa, Uvaria concava, Uvaria membranacea, Annonaceae, essential oil composition, caryophyllene oxide, spathulenol, [alpha]-pinene, [beta]-pinene, pinocarvone, trans-pinocarveol, sabinene, [alpha]-humulene, [beta]-caryophyllene.

Introduction

The family Annonaceae is quite diverse in Australia with over 50 species being present (L.W. Jessup, pers. comm. 1996). Virtually all of the Australian species occur in rainforest communities, with the vast majority being found in northeastern Queensland. Some Asian species of Annonaceae are economically important as sources of edible fruit and aromatic oils (1,2); however, the species indigenous to Australia have yet to be exploited commercially with little being known about their edibility or chemistry. Some are important as hostplants for a range of Australian butterflies (3). As part of our ongoing examination of the Australian flora for essential oils, the Queensland species of Artabotrys, Cananga, Cyathostemma, Goniothalamus, Mitrephora and Uvaria, which are represented in Australia by either one or two species, are reported in this paper. Studies on the remaining, more speciose genera of Australian Annonaccae have been previously published (4-9).

The genus Artabotrys R.Br. has about 100 species in the Paleotropics (1). All species are climbers and generally occur in rainforest communities. Arldhotrys was included in the Xylopia group of annonaceous genera that are characterized by valvate sepals and petals and spoon-shaped petals with a concave base that is coherent around the reproductive organs (1). Other genera in this group include Xylopia L., Anaxagorea A.St.Hil., Pseudartabotrys Pellegrin, Cyathocalyx Champ, ex Hook. f. et Thomson, Drepananthus Maingay ex Hook. f. et Thomson and Diclinanona Diels. The gen us Anaxagorea is thought to be basal in the Annonaceae (10), hence it may be inferred that other genera that are related to it, are also basal. Little is known about the potential uses or chemistry of the species of Artabotrys. The flowers of A. hexapetalus (L.f.) Bhand. from the Indian subcontinent are used to make a stimulant tea (2) and arc also apparently useful in the treatment of cholera (11). A single, as yet undescribcd, species of Artabotrys occurs in Australia and is restricted to the Iron and McIlwraith Ranges of Cape York Peninsula in Queensland. Artabotry sp. (Claudie River B.Gray 3240) is a large canopy liane and grows in complex notophyll vineforests on alluvium. There have been reports on the composition of the root and stem oils (12,13) and several on the leaf oil of A. odoratissimus which would appear to be quite variable (14-17) with the exception of this extra-Australian species of Artabotrys there has been no other work on the leaf oils of this genus.

The genus Cananga (DC) Hook. f. et Thomson comprises two species distributed from tropical Asia through Malesia to Australia (2). Cananga was included in the Cananga group of Annonaceous genera by Kessler (1), a group that was characterized by axillary flowers with valvate sepals and petals, anther connectives with a tongue-shaped apex and several lateral ovules. Other genera in the group were Bocageopsis R.E.Fries, Dielsiothamnus R.E.Fries and Onychopetalum R.E.Fries. One species, C. odorata (Lam.) Hook. f. et Thomson, occurs in Australia and is widespread over Malesia (e.g. Indonesia, the Philippines, New Guinea) and parts of Melanesia (Solomon Islands, Fiji, Vanuatu). In Australia, C. odorata is restricted to northeast Queensland from Iron Range, Cape York Peninsula in the north, to Mission Beach in the south. Plants form trees up to 15 m tall and are encountered in lowland rainforest (complex notophyll or mesophyll vineforests) on metamorphics and alluvia. The flowers of C. odorata (Lam.) Hook.f. are well known as the source of ylang-ylang or cananga oil, a material widely used in the perfumery industry. While an enormous amount of work has been done on these commercially important flower oils (18), there is but a single report describing the leaf oils of this species (19). There is an extensive ethnobotanical use of different parts of this plant, particularly in Malesia and Melanesia (20).