Cyanidin 3 o xyloside

The following HPLC- or LC-MS-grade reagents were used for analyses: acetonitrile, L-ascorbic acid, methanol (Sigma-Aldrich, Poland), acetic acid (Baker, Poland), and formic acid (VWR Int., Poland). The qualitative and quantitative content of polyphenolic compounds was determined with the following standards: 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, chlorogenic acid, caffeic acid, gallic acid, isovanilic acid, kaempferol, luteolin, neochlorogenic acid, orientin (luteolin-8-glucoside), p-coumaric acid, procyanidin B2, quercetin, quercetin-3-O-glucoside (Sigma-Aldrich, Poland), (+)-catechin, (–)-epicatechin, quercetin-3-O-galactoside, quercetin-3-O-rutinoside, quercetin-3-O-vicianoside (Extrasynthese, France), cyanidin-3-O-arabinoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside (Polyphenols Laboratories AS, Norway) and cyanidin-3-O-xyloside (Toronto Research Chemicals, Canada).

Chemical reagents (acetonitrile, L-ascorbic acid, methanol, acetic acid, and formic acid) were purchased from Sigma-Merck, Poznań, Poland. For the qualitative and quantitative content of polyphenols the following standards were used: gallic acid, caffeic acid, isovanilic acid, chlorogenic acid, neochlorogenic acid, p-coumaric acid, 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, orientin (luteolin-8-glucoside), quercetin, quercetin-3-O-glucoside, procyanidin B2, luteolin, kaempferol (Sigma-Aldrich, Poznań, Poland), cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, cyanidin-3-O-arabinoside (Polyphenols Laboratories AS, Sandnes, Norway), cyanidin-3-O-xyloside (Toronto Research Chemicals, North York, ON, Canada), quercetin-3-O-galactoside, quercetin-3-O-vicianoside, quercetin-3-O-rutinoside, (+)-catechin and (−)-epicatechin (Extrasynthese, Genay, France). All other chemicals were of analytical grade.