Flavokavain B from the rhizome of Alpinia mutica Roxb

Abstract

The title compound [systematic name: (E)-1-(2-hydroxy-4,6-dimethoxyphenyl)- 3-phenylprop-2-en-1-one], C17H16O4, has an aromatic ring at both ends of the -CH= CH-C(=O)- fragment with the -CH=CH- bond in a trans configuration. The phenyl ring is nearly coplanar with this fragment [dihedral angle 4.8 (3) °] as is the hy-droxy-ldimeth-oxy-lphenyl unit [dihedral angle 6.3 (3) °]. The hy-droxy group is the donor in an intra-molecular hydrogen bond to the double-bonded O atom.