*Department of Pharmacognosy, Medical University, 80-416 Gdańsk, ul. Gen. J. Hallera 107, Poland
**Faculty of Chemistry, Technical University, 80-952 Gdańsk, ul. Narutowicza 11, Poland

The oil and fatty acid content of the fruit of seven Asteraceae species (Arcticum nemorosum Lay. et Court.; Cosmos bipinatus Cav.; Echinacea purpurea Moench.; Inula helenium L.; Rudbeckia hirta L.; Taraxacum officinale Web.; Vernonia fasciculata Michx.) were studied. Relative densities (d₂₀), refractive indices (n_D²⁰), iodine numbers (IN) and acid numbers (AN) of the examined oils were determined. GLC was used for the identification and quantification of fatty acids after methylation with boron trifluoride in methanol.

The fruit of a commonly used healing plant E. purpurea yielded the largest quantity of oil (30.92%). The oil-content of three other fruits was also over 20% (C. bipinatus 22.4%; T. officinalem, 21.7%; R. hirta, 26.6%). The fruit of A. nemorosum yielded 18.4% oil. The oil-content of I. helenium and V. fasciculata was very low (5.07 and 5.19%, respectively).

A high essential fatty acid (EFA)-content was typical of all the oils examined (from 63.95% for C. bipinatus to 85.9% for R. hirta). All the plants examined, which belonged to various genera and species of the Asteraceae family, had a high linoleic acid content (the main EFA in the oils), which seemed to be typical of the Asteraceae family, but not of the lower range of classification. This fact could be very valuable for further chemotaxonomic research on this family.