Two new norsesquiterpenes from Ligularia lapathifolia.

Two new norsesquiterpenes were isolated from the extracts of the roots and rhizomes of Ligularia lapathifolia (Franch.) Hand.-Mazz. Their structures were identified as 2-acetyl-3a-methyl-5-(2-methyl-but-2-enoyloxy)-3a,4,5,6,7,7a-hexahydro-H-indene-4-carboxylic acid (1) and 2-acetyl-8a-methyl-2-(2-methyl-but-2-enoyloxy)-6-oxo-1,2,3,4,4a,5,6,8a-octahydro-naphthalene-1-carboxylic acid (2), respectively, on the basis of spectral data and for 1 by single-crystal X-ray analysis.