| Popis: |
This study aimed to characterization of the major anthocyanins (3-monoglucosides, 3-acetylglucosides, and 3-coumaroylglucosides), pyranoanthocyanins and hydroxyphenyl-pyranoanthocyanins in Vranec wines during aging of three years. The HPLC-DAD–ESI-MSn technique was used for identification of the analytes. Anthocyanins presented mass spectra characterized with two signals, molecular ion M+ and fragment ions [M-162]+, [M-204]+ and [M-308]+ which resulted from the loss of glucose, acetylglucose and p-coumaroylglucose groups, respectively. The pyranoanthocyanins derived from pyruvic acid, called 10-carboxy-pyranoanthocyanins or A-type vitisins, such as 10-carboxy-pyranomalvidin-3-glucoside (vitisin A), 10-carboxy-pyranomalvidin-3-acetylglucoside (acetyl-vitisin A) and 10-carboxy-pyranomalvidin-3-p-coumaroylglucoside (p-coumaroyl-vitisin A) were identified according to their molecular ions (M+ ) and the characteristic fragment ([M+H]+ = m/z 399). B-type vitisins, resulting from cycloaddition reaction between anthocyanins and acetaldehyde, including pyranomalvidin-3-glucoside (vitisin B) and pyranomalvidin-3- acetylglucoside (acetyl-vitisin B), presented molecular signals M+ at m/z 517 and 559 and producing a fragment ion at m/z 355 by loss of glucoside (162u) and acetylgucoside (204u) groups, respectively. Moreover, six hydroxyphenyl-pyranoanthocyanins produced in the reaction of caffeic acid (10-(3′′′,4′′′-dihydroxyphenyl)-pyranomalvidin-3-glucoside, 10-(3′′′,4′′′-dihydroxyphenyl)-pyrano malvidin-3-acetylglucoside and 10-(3′′′,4′′′-dihydroxyphenyl)-pyrano malvidin-3-p-coumaroylglucoside) and p-coumaric acid (10-(4′′′-monohydroxyphenyl) derivatives of pyranomalvidin-3-glucoside, pyranomalvidin-3-acetylglucoside and pyranomalvidin-3-p-coumaroylglucoside) with different anthocyanins, were detected in the wines. |
