Acylated flavonol tetraglycosides from Delphinium gracile

Abstract

An ethanol extract of the aerial parts of Delphinium gracile DC. yielded five flavonol glycosides quercetin-3- O-{[β- d-xylopyranosyl (1 → 3)-4- O-(E- p-caffeoyl)-α- l-rhamnopyranosyl (1 → 6)][β- d-glucopyranosyl (1 → 2)]}-β- d-glucopyranoside ( 1), quercetin-3- O-{[β- d-xylopyranosyl (1 → 3)-4- O-(E- p-coumaroyl)-α- l-rhamnopyranosyl (1 → 6)][β- d-glucopyranosyl (1 → 2)]}-β- d-glucopyranoside ( 2), quercetin-3- O-{[β- d-xylopyranosyl (1 → 3)-4- O-(Z- p-coumaroyl)-α- l-rhamnopyranosyl (1 → 6)][β- d-glucopyranosyl (1 → 2)]}-β- d-glucopyranoside ( 3), kaempferol-3- O-{[β- d-glucopyranosyl (1 → 3)-4- O-(E- p-coumaroyl)-α- l-rhamnopyranosyl (1 → 6)][β- d-glucopyranoside-7- O-(4- O-acetyl)-α- l-rhamnopyranoside ( 4) kaempferol-3- O-{[β- d-glucopyranosyl (1 → 3)-4- O-(E- p-coumaroyl)-α- l-rhamnopyranosyl (1 → 6)][β- d-glucopyranoside-7- O-(4- O-acetyl)-α- l-rhamnopyranoside ( 5) in addition to 4-(β- d-glucopyranosyloxy)-6-methyl-2H-pyran-2-one ( 6) and rutin. Structures were elucidated by spectroscopic methods.