O-Galloyl-C-glycosylflavones from Pelargonium reniforme.
The unique series of C-2''-acylated C-glycosylflavones is extended by the discovery of the C-8-glucosyl derivatives 2''-O-galloylvitexin and 2''-O-galloylorientin and their C-6 analogues 2''-O-galloylisovitexin and 2''-O-galloylisoorientin, representing the first described O-galloyl-C-glycosylflavones. They are accompanied in the aerial parts of Pelargonium reniforme by the known non-galloylated parent analogues vitexin, orientin, isovitexin and isoorientin, as well as several known flavonoid-O-glycosides. The structures of these compounds were established from spectroscopic studies. Differentiation between C-glycosylation at C-6 and C-8 is discussed on the basis of the effects of dynamic rotational isomerism.
Latté
Klaus Peter
KP
Institut für Pharmazie, Pharmazeutische Biologie, Freie Universität Berlin, Konigin-Luise-Str. 2+4, Berlin 14195, Germany.
Ferreira
Daneel
D
Venkatraman
M S
MS
Kolodziej
Herbert
H
D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism
D005419:Flavonoids