Essential Oils from the Leaves of Bosistoa F. Muell. ex Benth. (Rutaceae)

The leaf oils for species in the genus Bosistoa have been examined by GC and GC/MS. Bosistoa brassii produced a sesquiterpenoid leaf oil, the principal components of which were beta-caryophyllene (2-12%), alpha-humulene (1-18%,) and bicyclogermacrene (trace - 24%). Bosistoa floydii produced a leaf oil (in poor yield) dominated by alpha-pinene (46-67%). The leaf oil of B. medicinalis contained significant amounts of alpha-pinene (13-57%). The principal sesquiterpene present in the oil was beta-caryophyllene (1-9%). Bosistoa pentacocca, in both varieties, produced a leaf oil devoid of monoterpenes. The principal components in the leaf oil of this species were delta-cadinene (6-11%), alpha-copaene (2-7%), germacrene D (4-14%) and alpha-cadinol (2-8%). The leaf oils from B. transversa were variable, but the majority contained significant amounts of monoterpenes, with alpha-pinene (24-83%) being the principal component. The oil yields in all cases were poor (0.02-0.3%). Recommendations for taxon recognition in Bosistoa are made.