The aerial parts of ARCTOTIS ARCTOTOIDES afforded eight known sesquiterpene lactones and three new ones, the 11beta,13-dihydroguaianolides 9 and 10 as well as the chlorohydrine 8. Furthermore two 2Z-farnesol derivatives 12 and 13 were isolated. The structures were elucidated by highfield (1)H-NMR.
Three of ten sesquiterpene lactones isolated from the herb of Arctotis fastuosa (Asteraceae) belong to the heliangolide series. The first was identified as hirsutolide, the second is new and named dihydrohirsutolide, and the third, dichloromethyldihydrohirsutolide, is an artifact. The known degraded