Glycosidically Bound Norisoprenoids from Vitis vinifera Cv. Riesling Leaves

Article abstract of DOI:10.1021/jf00041a004

HRGC and HRGC-MS identifications of glycosidically bound Riesling leaf constituents were achieved after extraction with MeOH, Amberlite XAD-2 adsorption, and subsequent enzymatic hydrolysis of the glycoconjugates.Among the enzymatically liberated aglycons 23 bound C₁₃ norisoprenoids were identified.With the aid of multilayer coil countercurrent chromatography (MLCCC) five major C₁₃ glycosides were purified, and their structures were elucidated by high-field NMR, i.e., the β-D-glucopyranosides of vomifoliol, 4,5-dihydrovomifoliol, 3-hydroxy-5,6-epoxy-β-ionone, grasshopper ketone, and 3-oxo-megastigman-9-ol.The latter glucoside with a saturated megastigmane skeleton is reported here for the first time.In addition, the β-D-glucopyranosides of benzyl alcohol and raspberry ketone have been isolated.