A new C-noresoprenoid intramolecular acetal in Riesling wine.

A new [.sup.13C-norisoprenoid] intramolecular acetal in Riesling wine

The recent finding[1] in Riesling wine of 40 norisoprenoid compounds in glycoconjugated form has demonstrated that these, apparently carotenoid-derived compounds, are the most numerous and abundant terpenoids of wines of this variety. Such glycosides, on mild acid hydrolysis, are capable of generating many volatiles, among which are the known wine flavour constituents damascenone, vitispirane and 1,1,6-trimethyl-1,2-dihydronaphthalene.[2] In addition to these three compounds, a fourth norisoprenoid volatile was observed when the glycoconjugates of Riesling wine were subjected to hydrolysis at pH 3.[2] This fourth compound, which is referred to in the authors' laboratory as Riesling Acetal, was …