title: Flavonol tetraglycosides and other constituents from leaves of Styphnolobium japonicum (Leguminosae) and related taxa.
abstract: Two flavonol tetraglycosides comprising a trisaccharide at C-3 and a monosaccharide at C-7 were isolated from the leaves of Styphnolobium japonicum (L.) Schott and characterised as the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-glucopyranoside-7-O-alpha-rhamnopyranosides of quercetin and kaempferol. The 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-galactopyranoside-7-O-alpha-rhamnopyranoside of kaempferol, the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-glucopyranosides of kaempferol and quercetin and the 3-O-alpha-rhamnopyranosyl(1-->2)[alpha-rhamnopyranosyl(1-->6)]-beta-galactopyranoside of kaempferol were also obtained from this species for the first time. Some or all of these flavonol tetra- and triglycosides were detected in 17 of 18 specimens of S. japonicum examined from living and herbarium material, although the most abundant flavonoid in the leaves was generally quercetin 3-O-alpha-rhamnopyranosyl(1-->6)-beta-glucopyranoside (rutin). The triglycosides, but not the tetraglycosides, were detected in herbarium specimens of Styphnolobium burseroides M. Sousa, Rudd & Medrano and Styphnolobium monteviridis M. Sousa & Rudd, but specimens of Styphnolobium affine (Torrey & A. Gray) Walp. contained a different profile of flavonol glycosides. The flavonol tetra- and triglycosides of S. japonicum were also present in leaves of Cladrastis kentukea (Dum. Cours.) Rudd, a representative of a genus placed close to Styphnolobium in current molecular phylogenies. An additional constituent obtained from leaves of Styphnolobium japonicum was identified as the maltol derivative, 3-hydroxy-2-methyl-4H-pyran-4-one 3-O-(4'-O-p-coumaroyl-6'-O-(3-hydroxy-3-methylglutaroyl))-beta-glucopyranoside.
authors.affiliation: Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK. g.kite@kew.org
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Kite
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Stoneham
authors.forename: Nigel C
authors.initials: NC
authors.lastname: Veitch
mesh_terms: D005591:Chemical Fractionation; D007887:Fabaceae / Q000737:chemistry*; D044948:Flavonols / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification; D044949:Kaempferols / Q000737:chemistry* / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D044948:Flavonols; D006027:Glycosides; D044949:Kaempferols; D010936:Plant Extracts; D011794:Quercetin