title: An 8-hydroxylated external flavone and its 8-O-glucoside from Becium grandiflorum.
abstract: The major vacuolar flavonoid of a greenhouse-grown plant of Becium grandiflorum has been identified as the 8-O-glucoside of isothymusin (5,8,4'-trihydroxy-6,7-dimethoxyflavone), while the major external flavonoids in the diethyl ether surface wash of the same plant are found to be isothymusin and cirsimaritin (5,4'-dihydroxy-7,8-dimethoxyflavone). Although isothymusin is already known as a conversion product of thymusin (5,6,4'-trihydroxy-6,7-dimethoxyflavone) formed by means of the Wessely-Moser rearrangement, this is the first report of isothymusin as a plant constituent, both as aglycone and glycoside. The biogenetic and chemotaxonomic implications of the occurrence of these flavonoids in B.grandiflorum are briefly discussed.
authors.affiliation: Jodrell Laboratory, Royal Botanic Gardens, Surrey, U.K.
authors.forename: R J
authors.initials: RJ
authors.lastname: Grayer
authors.forename: N C
authors.initials: NC
authors.lastname: Veitch
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D006900:Hydroxylation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005419:Flavonoids; D005960:Glucosides; D010936:Plant Extracts