Cytotoxic constituents of the roots of Zingiber cassumunar Roxb

Two phenylbutenoids, 4-(3',4'-dimethoxyphenyl)buta-1,3-diene (1) and 4-(2',4',5'-trimethoxyphenyl)buta-1,3-diene (2), were isolated from the roots of Zingiber cassumunar Roxb. (Zingiberaceae), as active constituents by bioassay-guided fractionation using a cytotoxicity assay against the HT1080 (human fibrosarcoma) cells. The isolates 1 and 2 exhibited a significant cytotoxicity with IC$\sub$50/ values of 0.71 and 0.74$\mu\textrm{g}$/$m\ell$, respectively, which are comparative to the positive control ellipticine (IC$\sub$50/=1.1 $\mu\textrm{g}$/ml). (omitted)