The leaf oils of the Australian species of Neolitsea (Lauraceae)

The leaf oils of the Australian species of Neolitsea have been investigated, All species gave oils that were sesquiterpenoid in nature. Neolitsea australiensis produced an oil in which the major components were bicyclogermacrene (12-16%) and guaiol (13-17%). Many other sesquiterpenes were present in amounts of less than 5%. N. brassii gave a very similar oil in which the major components were bicyclogermacrene (11-15%), cubenol (610%) and guaiol (7-10%). The possibility that N. australiensis and N. brassii are conspecific is discussed. N. dealbata, a species that has a wide north-south distribution, gave different oils from the northern and southern populations. From the northern populations, the major components were gennacrone (approximately 50%), bicyclogermacrene (12-35%) and spathulenol (4-38%),with one population replacing the majority of germacrone by furanogermenone (43%). From the southern populations the major components were beta-eudesmol (3-30%) and spathulenol (5-30%). Germacrone was not detected in the southern populations. The oil yields for all species were 0.2-0.6%, based on fresh weight.