Generation of (<i>E</i>)-1-(2,3,6-Trimethylphenyl)buta-1,3-diene from C<sub>13</sub>-Norisoprenoid Precursors
Agnieszka Cox, George K. Skouroumounis, Gordon M. Elsey, Michael V. Perkins, Mark A. Sefton
Journal of Agricultural and Food Chemistry
Abstract
Three C(13)-norisoprenoid compounds, 3,6,9-trihydroxymegastigma-4,7-diene (6), 3,4,9-trihydroxymegastigma-5,7-diene (4), and the actinidols (8), have all been synthesized and subjected to acid hydrolysis. All three were shown to generate (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene (1) under wine conservation conditions. At 45 degrees C, approximately 4000-5000 ng/L of 1 was formed from 1.0 mg/L of precursor, after 173 days, while at 25 degrees C more wine-like amounts (200-600 ng/L) were observed. A glucoside, 4,5-dihydrovomifoliol-C(9)-beta-d-glucopyranoside (9b), was isolated from grapevine leaves by multilayer coil countercurrent chromatography (MLCCC), and its stereochemistry was deduced as being (5R, 6S, 9R) by NMR and CD spectroscopy. Hydrolysis of this glucoside produced 1, but in quantities insufficient to account for the levels observed in wine.
Extracted Claims
2 claims extracted from this paper into the knowledge graph
C13-norisoprenoid compounds generate (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene
“At 25 degrees C more wine-like amounts (200-600 ng/L) were observed”
C13-norisoprenoid compounds generate (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene
“At 45 degrees C, approximately 4000-5000 ng/L of 1 was formed from 1.0 mg/L of precursor, after 173 days”