Cytotoxic terpenes and lignans from the roots of Ainsliaea acerifolia.

The chromatographic separation of the MeOH extract of the roots of Ainsliaea acerifolia (Compositae) led to the isolation of six known terpenes and two known lignans. Their structures were identified by spectroscopic methods as mokko lactone (1), betulonic acid (2), betulinic acid (3), zaluzanin C (4), 1beta-hydroperoxygermacra-4(15),5,10(14)-triene (5), pluviatilol (6), (+)-syringaresinol (7), and glucozaluzanin C (8). Compounds 1 approximately 4 and 8 showed non-specific significant cytotoxicity against five human tumor cell lines with ED50 values ranging from 0.36 approximately 5.54 microg/mL.