Immunotoxic sesquiterpene lactone from Carpesium rosulatum Miq.

The whole plants of Carpesium rosulatum were chloroform extracted and the isolated sesquiterpene lactones and immunotoxicity effects were studied. The structures and stereochemistry of these compounds were established on the basis of analysis of spectra including mp, [α](D)(25), IR, UV, EI-MS, MS, (1)H-NMR, (13)C-NMR and some chemical transformations as follows: 1 (4β,10α-dihydroxy-guaia-8α,12-olide), 2 (4β,10α-dihydroxy-1(2),11 (13)-guaiadien -8α,12-olide), 3 (3β,8β-dihydroxy-1α,5α-guaian-10(14)-ene-6α,12-olide). 4 (2β,5-epoxy-5,10-dihydroxy-6α,9β-diangeloyloxy-germacran-8α,12-olide) The chloroform extracted had a significant toxic effect against early fourth-stage larvae of Aedes aegypti L with an LC(50) value of 13.11 ppm and an LC(90) value of 20.33 ppm. The results could be useful in search for newer, safer, and more effective natural immunotoxicity agents against A. aegypti.