Preparative isolation and purification of two phenylbutenoids from the rhizomes of Zingiber cassumunar by upright counter-current chromatography.

Two phenylbutenoids, (E)-4-(3',4'-dimethoxyphenyl)but-3-enyl acetate and (E)-4-(3',4'-dimethoxyphenyl)but-1,3-diene, were separated from the rhizomes of Zingiber Cassumunar using a preparative upright counter-current chromatography (CCC). With a two-phase solvent system composed of light petroleum (b.p. 60-90 degrees C)-ethanol-diethyl ether-water (5:4:2:1, v/v), 150 mg of (E)-4-(3',4'-dimethoxyphenyl)but-3-enyl acetate and 175 mg of (E)-4-(3','-dimethoxyphenyl)but- 1,3-diene with the purity of 98.7 and 95.1%, respectively, were obtained from 600 mg of the crude sample of Z. Cassumunar in a single-step separation. Structures of these two compounds were identified by ESI-MS, 1H NMR and 13C NMR.