Cytotoxic sesquiterpenoids from Eupatorium chinense

Ten new sesquiterpenoids, namely, eupachinilides A-J (1-10), together with seven known sesquiterpenoids, eupachifolin D (11), budlein B (12), 8 beta-(4'-hydroxytiglyloxy)-2 beta-hydroxy-1 alpha H,5 alpha H,6 beta H,7 alpha H-guai-3,10(14),11(13)-trien-6,12-olide (13), 1,10-hydrobahia (14), 2 alpha-hydroxyeupatolide (15), eupaserrin (16), and mollisorin B (17), were isolated from the whole plant of Eupatorium chinense. Their structures were elucidated mainly by spectral methods, especially 2D NMR techniques. Eupachinilides A (1), E (5), F (6), and I (9) exhibited moderate cytotoxic activities against several tumor cell lines. The structures assigned previously for eupachifolins B (11a), C (13a), and D (11) were revised by spectral analysis and 2D NMR techniques.