Application of Droplet Countercurrent Chromatography to the Analysis of Conjugated Forms of Terpenoids, Phenols, and Other Constituents of Grape Juice

Abstract

Minor polar constituents isolated from juices of the Vitis vinifera, cv. Rhine Riesling, Muscat of Alexandria, and Chardonnay, were separated by droplet countercurrent chromatography (DCCC). Analyses were made of compounds in the DCCC fractions by GC-MS after enzymic hydrolysis and by NMR after acetylation and further liquid chromatography. These procedures have allowed identification of conjugated forms, including glycosides, of monoterpenoids, C13norisoprenoids, phenols, and other compounds. Among the grape constituents identified were (E)-6-hydroxy-2,6-dimethylocta-2,7-dien-l-yl-β-D-gluco-pyranoside and the corresponding 6-O-α-arabinofuranosyl-β-D-glucopyranoside, l-methyl-l-(trans-5′;-me..