Characterization of flavonols in cranberry (Vaccinium macrocarpon) powder.
Flavonoids were extracted from cranberry powder with acetone and ethyl acetate and subsequently fractionated with Sephadex LH-20 column chromatography. The fraction eluted with a 60% methanol solution was composed primarily of phenolic constituents with maximum absorbance at 340 nm. A high-performance liquid chromatography procedure was developed, which resolved 22 distinct peaks with UV/vis and mass spectra corresponding to flavonol glycoside conjugates. Six new constituents not previously reported in cranberry or in cranberry products were determined through NMR spectroscopy to be myricetin-3-beta-xylopyranoside, quercetin-3-beta-glucoside, quercetin-3-alpha-arabinopyranoside, 3'-methoxyquercetin-3-alpha-xylopyranoside, quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside, and quercetin-3-O-(6' '-benzoyl)-beta-galactoside. Quercetin-3-O-(6' '-p-coumaroyl)-beta-galactoside and quercetin-3-O-(6' '-benzoyl)-beta-galactoside represent a new class of cranberry flavonol compounds with three conjugated components consisting of a flavonol, sugar, and carboxylic acid (benzoic or hydroxycinnamic acids). This is also the first report identifying quercetin-3-arabinoside in both furanose and pyranose forms in cranberry. Elucidation of specific flavonol glycosides in cranberry is significant since the specificity of the sugar moiety may play a role in the bioavailability of the flavonol glycosides in vivo.
Vvedenskaya
Irina O
IO
Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901, USA.
Rosen
Robert T
RT
Guido
Jane E
JE
Russell
David J
DJ
Mills
Kent A
KA
Vorsa
Nicholi
N
D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011208:Powders / Q000737:chemistry; D029799:Vaccinium macrocarpon / Q000737:chemistry*
D044948:Flavonols; D011208:Powders