Eremophilane sesquiterpenes from Ligularia macrophylla

New eremophilane sesquiterpenes, 6 beta-sarracinoyloxy-1 beta,10 beta-epoxy-furanoeremophilane (1), 6 alpha-angeloyloxy-10 beta H-furanoeremophil-1-one (2), 1 alpha-hydroxy-9-deoxycacalol (3), and 1 beta-hydroxy-11(R,S)-8-oxoeremophil-6,9-dien-12-al (4a+4b), together with five known sesquiterpenes (5-9) were isolated from the roots and rhizomes of Ligularia macrophylla. The structures were elucidated by spectroscopic methods including 2D NMR techniques, and the structure of 1 was confirmed by a single-crystal X-ray diffraction experiment. The compounds were also evaluated for cytotoxic activity against human lung carcinoma (A-549) and human breast adenocarcinoma (MCF-7) and were found to show only very weak cytotoxicity.