title: 3,5,3'-Trihy-droxy-4'-meth-oxy-7-(3-methyl-but-2-en-yloxy)flavone.
abstract: The title compound pteleifolosin C, C(21)H(20)O(7), was isolated from the petroleum ether-soluble fraction of an indigenous Chinese tree Melicope pteleifolia (Rutaceae). The dihedral angle between the benzene rings is 2.7 (2)°. Intra-molecular O-H⋯O hydrogen bonds occur. In the crystal, mol-ecules are linked by inter-molecular O-H-O hydrogen bonds.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Zhu
authors.forename: Shao-Qian
authors.initials: SQ
authors.lastname: Liu