2006/09/09 by Fulvio Mattivi, Raffaele Guzzon, Urška Vrhovšek +2 · 2 citations
Agricultural and Biological Sciences · Medicine · Biochemistry, Genetics and Molecular Biology · #Fermentation and Sensory Analysis #Phytochemicals and Antioxidant Activities #Plant Gene Expression Analysis
paper · doi:10.1021/jf061538c
openalex publication_date 2006/09/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/08
Flavonols are products of the flavonoid biosynthetic pathway, which also give rise to anthocyanins and condensed tannins in grapes. We investigated their presence in the berry skins of 91 grape varieties (Vitis vinifera L.), in order to produce a classification based on the flavonol profile. The presence of laricitrin 3-O-galactoside and syringetin 3-O-galactoside in red grapes is reported here for the first time. In red grapes, the main flavonol was quercetin (mean = 43.99%), followed by myricetin (36.81%), kaempferol (6.43%), laricitrin (5.65%), isorhamnetin (3.89%), and syringetin (3.22%). In white grapes, the main flavonol was quercetin (mean = 81.35%), followed by kaempferol (16.91%) and isorhamnetin (1.74%). The delphinidin-like flavonols myricetin, laricitrin, and syringetin were missing in all white varieties, indicating that the enzyme flavonoid 3',5'-hydroxylase is not expressed in white grape varieties. The pattern of expression of flavonols and anthocyanins in red grapes was compared, in order to gain information on the substrate specificity of enzymes involved in flavonoid biosynthesis.