Bevan Wilson

Novel monoterpene disaccharide glycosides of Vitis vinifera grapes and wines

Abstract β-Rutinosides (6-O-α- l -rhamnopyranosyl-β- d -glucopyranosides) and 6-O-α- l -arabinofuranosyl-β- d -glucopyranosides of geraniol, nerol and linalol have been isolated and characterized in Muscat of Alexandria grapes and wine. These monoterpene disaccharide glycosides, which are precursors of linalol oxidation state monoterpenes of the grape, are also present in another non-muscat Vitis vinifera var. Rhine Riesling.

Use of C18 reversed-phase liquid chromatography for the isolation of monoterpene glycosides and nor-isoprenoid precursors from grape juice and wines

Abstract Glycosidic derivatives of monoterpene flavourants of grapes and wines can be preparatively isolated by selective retention on a C 18 -bonded reversed-phase adsorbent. These components can thus be concentrated by a factor of 20,000 in a single chromatographic step. Class separation of monoterpene glycosides at different oxidation levels can also be achieved on the reversed-phase adsorbent. Teh process has also led to the discovery of precursors of 2-phenylethanol, benzyl alcohol, damascenone, vitispirane and 1,1,6-trimethyl-1,2-dihydronaphthalene. Additionally, many other related nor-isoprenoid compounds not previously known in grapes have been observed.

Glycosides of 2-phenylethanol and benzyl alcohol in Vitis vinifera grapes

Abstract β-Rutinosides and 6- O -α- l -arabinofuranosyl-β- d -glucopyranosides of 2-phenylethanol and benzyl alcohol have been found to co-occur with similar disaccharide glycosides of monoterpenes in Vitis vinifera vars. Muscat of Alexandria and Rhine Riesling. β- d -Glucopyranosides of these two alcohols were also identified in the fruit.

New linalool derivatives in muscat of alexandria grapes and wines

Abstract The CHCl 3 extract of Muscat of Alexandria grapes as well as extracts of wines made from these grapes were found to contain 3,7-dimethyloct-1-en-3,6,7-triol, 3,7-dimethyloct-1-en-3,7-diol, 3,7-dimethylocta-1,7-dien-3,6-diol and 3,7-dimethylocta-1,5-dien-3,7-diol.

3-oxo-α-ionol, vomifoliol and roseoside in Vitis vinifera fruit

Abstract 3-Oxo-β-ionol, vomifoliol and dehydrovomifoliol were identified for the first time in fruit from Vitis vinifera . The last named compound was mainly present free in the juice while the others existed predominantly as conjugates. In the case of vomifoliol, the conjugation was with glucose, i.e. as roseoside. Hydrolytic studies on 3-oxo-α-ionol and vomifoliol gave a range of compounds which have been recognized as fruit and plant products.

The actinidols: nor-isoprenoid compounds in grapes, wines and spirits

Abstract The isomeric actinidols, 2,2,6-trimethyl-8-(1-hydroxy)ethyl-7-oxabicyclo[4.3.0]nona-4,9-dienes, have been identified in steam distillates of juices from Vitis vinifera grape vars. Muscat of Alexandria, Chardonnay and Doradillo. The two major isomers of this compound, which were also commonly observed in wines and brandies, were tentatively identified as having a trans -stereochemistry about the dihydrofuran ring in the molecule.