Covalent anthocyanin-flavonol complexes from flowers of chive, Allium schoenoprasum.
The structures of eight anthocyanins have been determined in acidified methanolic extract of pale-purple flowers of chive, Allium schoenoprasum. Four of them have been identified as the anthocyanin-flavonol complexes (cyanidin 3-O-beta-glucosideAII) (kaempferol 3-O-(2-O-beta-glucosylFIII-beta-glucosideFII)-7-O-beta-gl ucosiduronic acidFIV) malonateAIII (AII-6-->AIII-1, FIV-2-->AIII-3), 1, (cyanidin 3-O-(3-O-acetyl-beta-glucosideAII) (kaempferol 3-O-(2-O-beta-glucosylFIII-beta-glucosideFII)-7-O-beta-gl ucosiduronic acidFIV) malonateAIII (AII-6-->AIII-1, FIV-2-->AIII-3), 2, and their 7-O-(methyl-O-beta-glucosiduronateFIV) analogous, 3 and 4. Pigments 1 and 2 are the first final identification of covalent complexes between an anthocyanin and a flavonol, while 3 and 4 are formed during the isolation process. The other four anthocyanins (5-8) were found to be the 3-acetylglucoside, 3-glucoside, 3-(6-malonylglucoside) and 3-(3,6-dimalonylglucoside) of cyanidin. The three latter pigments have earlier been identified as the major anthocyanins of the chive stem. The covalent anthocyanin-flavonol complexes show intramolecular association between the anthocyanidin (cyanidin) and flavonol (kaempferol) units, which influence the colour.
Fossen
T
T
Department of Chemistry, University of Bergen, Norway.
Slimestad
R
R
Ovstedal
D O
DO
Andersen
O M
OM
D000490:Allium / Q000737:chemistry*; D000872:Anthocyanins / Q000737:chemistry* / Q000302:isolation & purification; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010936:Plant Extracts / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013053:Spectrophotometry
D000872:Anthocyanins; D005419:Flavonoids; D006027:Glycosides; D010936:Plant Extracts