Isolation and identification of novel pyranoanthocyanins from black carrot (Daucus carota L.) juice.
Six novel pyranoanthocyanins were identified by HPLC-ESI-MSn in black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) juice. The two major compounds, namely, the vinylcatechol adducts of cyanidin 3-O-(6-O-feruloyl-beta-D-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside and cyanidin 3-O-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, respectively, were isolated by a combination of high-speed countercurrent chromatography with semipreparative HPLC. Their structures were fully elucidated by means of one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry. The four remaining pigments were characterized as the vinylphenol and vinylguaiacol adducts of cyanidin 3-O-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, the vinylguaiacol adduct of cyanidin 3-O-(6-O-feruloyl-beta-D-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, and the vinylcatechol adduct of cyanidin 3-O-(6-O-sinapoyl-beta-d-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside. These compounds are formed during storage of the juice through the direct reaction of either caffeic, ferulic, or coumaric acid with the respective genuine anthocyanins.
Institute of Food Chemistry, Technical University of Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany.
Michael
M
Schwarz
Victor
V
Wray
Peter
P
Winterhalter
D000872:Anthocyanins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D001628:Beverages; D002109:Caffeic Acids / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry; D018552:Daucus carota / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization
D000872:Anthocyanins; D002109:Caffeic Acids; D003373:Coumaric Acids; C004999:ferulic acid; C040048:caffeic acid