Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
Organ / tissue: stem
NCBI PubMed ID: 10775352Publication DOI: 10.1021/jf991171uJournal NLM ID: 0374755Publisher: American Chemical Society
Correspondence: souquet
ensam.inra.fr
Institutions: ISVV-INRA, Institut des Produits de la Vigne, Unité de Recherche Biopolymères et Arômes, Montpellier, France
Grape stems contain significant amounts of polyphenolic compounds, especially phenolic acids, flavonols, and flavanonols such as astilbin. The tannin content was characterized after the depolymerization reaction thiolysis. Tannins consisted of polymeric proanthocyanidins (up to 27 units) mainly consisting of (-)-epicatechin units along with smaller amounts of (+)-catechin, (-)-epicatechin gallate, and (-)-epigallocatechin. Flavanonols (astilbin) have been identified for the first time in stem and characterized by LC/MS and NMR. All phenolic compounds in grape stems were quantified by HPLC: quercetin 3-glucuronide was the most important, followed by catechin, caffeoyltartaric acid, and dihydroquercetin 3-rhamnoside (astilbin). Comparison was made of proanthocyanidin characteristics in different white and red grape varieties and also among parts of the cluster (skin, seed, and stem). Stem-condensed tannins were qualitatively intermediate between seed and skin but could not be differentiated between red and white varieties.
grape; stems; proanthocyanidins; flavanols; flavonols; flavanonols; phenolic acids
Structure type: monomer
Location inside paper: p. 1079, Table 5
Trivial name: isoquercitrin
Compound class: saponin glycoside, glycoside, flavonoid glycoside, flavonol glycoside, flavone glycoside
Contained glycoepitopes: IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: 13C NMR, 1H NMR, NMR-2D, TLC, enzymatic hydrolysis, acid hydrolysis, HPLC, optical rotation measurement, HR-FAB-MS
Related record ID(s): 68001, 68002, 68003, 68005, 68006, 68007
NCBI Taxonomy refs (TaxIDs): 29760Reference(s) to other database(s): CCSD:
49965, CBank-STR:953
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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