Leaf essential oils of the Queensland species of Phebalium (Rutaceae: Boronieae)

The leaf oils of the eight Queensland specific and subspecific taxa of Phebalium have been examined. Phebalium distans produced a variable oil, with alpha-pinene (0.8-42%) being the most abundant prominent monoterpene and bicyclogermacrene (12-22%) as the most significant sesquiterpene. In P. glandulosum subsp. glandulosum by far the major component is dihydrotagetone (75-95%). beta-Caryophyllene (9-20%) and bicyclogermacrene (7-23%) were the major components of P. longifolium. In P. nottii the principal monoterpene detected was alpha-pinene (25-42%), while the principal sesquiterpenes detectedwere guaiol (t-28%) and bulnesol (nil to 34%). The two monoterpene hydrocarbons, alpha-phellandrene (12-25%) and beta-phellandrene (14-15%), together with bicyclogermacrene (2-12%), elemol/hedycaryol (12-36%) were major components in the leaf oil of P. squamulosum subsp. squamulosum, while in P. squamulosum subsp. gracile, geijerene (4-8%) was present together with alpha-pinene (44-50%) and guaiol (9-11%). The leaf oil of P. whitei contained alpha-pinene (22-42%), limonene (1-12%) and bicyclogermacrene (11-20%) as major components. In P. woombye the main components were alpha-pinene (10-21%), beta-phellandrene (12-20%), bicyclogermacrene (11-20%) and germacrene D (5-10%).