Cytotoxic sesquiterpene lactones from Eupatorium lindleyanum.

Three new germacrane sesquiterpenes, eupalinolides C-E (1-3), along with three known germacrane sesquiterpenes, eupalinolide A (4), eupalinolide B (5), and 3beta-acetoxy-8beta-(4'-hydroxytigloyloxy)-14-hydroxycostunolide (6), were isolated from Eupatorium lindleyanum. They were tested for cytotoxicity against A-549, BGC-823, SMMC-7721, and HL-60 tumour cell lines. The results showed that these compounds demonstrated potent cytotoxicity. The structures of the compounds were elucidated by means of (1)H and (13)C NMR spectroscopic analysis, including 2D NMR experiments.