5,6-Dihydroxy-7,8-dimethoxyflavone

Abstract

The title compound (systematic name: 5,6-dihydroxy-7,8-dimethoxy-2-phenylchromen-4-one), C17H14O6, is a flavone that was isolated from the petroleum ether-soluble fraction of the rare traditional Chinese medicinal herb Saussurea involucrata. The flavone molecule is almost planar, with a dihedral angle between the planes of the benzopyran-4-one group and the attached phenyl group of 1.89 (6)°. The 5-hydroxy group forms a strong intramolecular hydrogen bond with the carbonyl group, resulting in a six-membered hydrogen-bonded ring. The 6-hydroxy group also forms an intramolecular O—H...O contact. In the crystal, the molecules are linked by O—H...O and C—H...O hydrogen bonds and π–π interactions [3.37 (2)–3.39 (2) Å], which build up a three–dimensional network.