Sesquiterpene Lactones, Inhibitors of Farnesyl Protein Transferase, Isolated from the Flower of Artemisia sylvatica

Five sesquiterpene lactones, 8-acetylarteminolide (1), artanomaloide (2), arteminones (3 and 4), and dehydromatricarin (5), were isolated from the methanolic extract of the flower of Artemisia sylvatica and characterized on the basis of their spectral data. New sesquiterpene lactone 1 was identified as a configurational isomer of artanomaloide (2), and the new arteminones 3 and 4 are determined as stereoisomers. 8-Acetylarteminolide (1) strongly inhibited FPTase with an IC50 of 1.8 μM, however, the other sesquiterpene lactones mildly inhibited the transferase with an IC50 of 22–300 μM.