Sesquiterpene Lactones and Phenylpropanoids from Cosmos pringlei<SUP>1</SUP>

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