Sesquiterpene lactones and phenylpropanoids from Cosmos pringlei.

Activity-directed fractionation of a phytotoxic extract from Cosmos pringlei led to the isolation of three new compounds, namely, 1'-isovaleroyloxy-4-O-isobutyryleugenol (1), zaluzanin C isobutyrate (2), and zaluzanin C isovalerate (3). In addition, mokko lactone, 1'-isobutiroyloxy-4-O-isobutyryleugenol (4), dehydrocostus lactone (5), costunolide (6), 15-isovaleroyloxycostunolide (7), 15-isobutiroyloxycostunolide (8), 1',2'-epoxy-3',4'-di-isobutyryl-Z-coniferyl alcohol, and 3beta-hydroxy-5alpha-pregn-16-en-20-one were obtained. The structures of the new compounds were established by spectral methods. Compounds 5-7 caused inhibition of radicle growth of seedlings of Amaranthus hypochondriacus.