Acylated flavone glycosides from Veronica.
A survey of the flavonoid glycosides of selected taxa in the genus Veronica yielded two new acylated 5,6,7,3',4'-pentahydroxyflavone (6-hydroxyluteolin) glycosides and two unusual allose-containing acylated 5,7,8,4'-tetrahydroxyflavone (isoscutellarein) glycosides. The new compounds were isolated from V. liwanensis and V. longifolia and identified using NMR spectroscopy as 6-hydroxyluteolin 4'-methyl ether 7-O-alpha-rhamnopyranosyl(1"'-->2")[6"-O-acetyl-beta-glucopyranoside] and 6-hydroxyluteolin 7-O-(6"-O-(E)-caffeoyl)-beta-glucopyranoside, respectively. Isoscutellarein 7-O-(6"'-O-acetyl)-beta-allopyranosyl(1"'-->2")-beta-glucopyranoside was obtained from both V. intercedens and V. orientalis and its 4'-methyl ether from V. orientalis only. Complete 1H and 13C NMR spectral assignments are presented for both isoscutellarein glycosides. Two iridoid glucosides new to the genus Veronica (melittoside and globularifolin) were also isolated from V. intercedens.
Department of Higher Plant Systematics, Institute of Botany, University of Vienna, Austria.
Dirk C
DC
Albach
Renée J
RJ
Grayer
Søren Rosendal
SR
Jensen
Fevzi
F
Ozgökce
Nigel C
NC
Veitch
D000215:Acylation; D047309:Flavones; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification*; D039823:Iridoids / Q000737:chemistry / Q000302:isolation & purification; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D032264:Veronica / Q000737:chemistry*
D047309:Flavones; D005419:Flavonoids; D006027:Glycosides; D039823:Iridoids; C043562:flavone