Hydrocarbons from Cirsium japonicum

Aplotaxene, dihydro-, tetrahydro- and hexahydro- aplotaxene, 1-pentadecene, cyperene, caryophyllene, thujopsene and α-himachalene were found in the root oil of Cirsium japonicum. The isolation of dihydro- and tetrahydro-aplotaxene is the first report from natural sources. The latter is a biogenetically important intermediate from oleic acid, to C17-acetylene compounds.