Isolation 8-damascenone precursor

Figure 2. The bioassay for 6-damascenone precursor isolated from Concord grapes.

Table II. Charm-based recoveries from a preparative isolation of p-damascenone precursor from 80 kg Concord grapes.

The precursor structures can be elucidated by HRGC/MS and HRGC/FTTR of the acetylated derivatives or aglycons, respectively. Very recently, direct LC/MS measurement of a non-derivatized precursor glycoside of (E)-B-damascenone isolated from apples has been reported [100]. Application of such techniques on precursor fractions from wine [97, 101]... 

Isolation of Two Glucosidic Precursors of B-Damascenone From Riesling Wine. 

Figure 7. Structures of two acetylenic precursors of B-damascenone 19 isolated from Riesling wine.

Isolation of Nonvolatile Precursors of /3-Damascenone from Grapes Using Charm Analysis... 

A bioassay for the precursor compound to p-damascenone, frartj-2,6,6-trimethyl-cyclohexa-1,3-dienyl- l-but-2-ene- 1-one, found in grape skins was developed based on the generation of free p-damascenone and the sensory technique charm. Thin layer, column, and high pressure liquid chromatography were used to separate the precursor from 80 kg of grapes, Vitis labruscana, Bailey cv. Concord. There was a 22,000 fold enrichment in the precursor in 3.7 g of isolate. 

If the precursor occurs at a concentration similar to that of p-damascenone, ca. 5 ng/g in thermally processed Concord grapes, its detection during isolation requires a... 

Vomifoliol (97) isolated from Rauwolfia vomitoria appears to be a degradation product of abscisic acid and possibly a precursor of theaspirone. Damas-cenone, a minor component of Bulgarian rose oil, was shown to be the cross-conjugated isomer (98) of dehydroionone. A tetrahydro-damascenone was prepared by treating a-ionone-7,8-oxide with hydrazine. ... 

Naef, R., Velluz, A., and Thommen, W. 1990. Isolation of a glucosidic precursor of damascenone from Lyceum hamifolium Mil. Tetrahedron Lett. 45 6521-22. 

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