The chemistry of wine polyphenolic C-glycosidic ellagitannins targeting human topoisomerase II.
Polyphenolic nonahydroxyterphenoyl-containing C-glycosidic oak ellagitannins are found in wine as a result of the aging of this beverage in oak-made barrels. Once in the slightly acidic wine (pH approximately 3-4), some of these complex natural products such as (-)-vescalagin (1), but not its C-1 epimer (-)-castalagin (2), can capture grape-derived nucleophilic entities such as ethanol, the flavanols catechin (10a) and epicatechin (10b), the anthocyanin oenin (13b), and the thiolic glutathione (16) to furnish condensation products with retention of configuration at the C-1 locus. A computer-aided rationale of this high diastereoselectivity is given. These condensation products can contribute to the modulation of organoleptic properties of the wine, as evidenced by the 23 nm bathochromic shift color absorbance observed with the novel oenin-based anthocyano-ellagitannin (15b). Hydrolysis of 1 under solvolytic conditions furnished another novel compound that we refer to as vescalene (21), in addition to the known (-)-vescalin (18). Of pharmacological importance is the fact that most of these found-in-wine water-soluble ellagitannin derivatives are much more potent than etoposide (VP-16) at inhibiting top2-mediated DNA decatenation in vitro (top2=topoisomerase II)). The known (-)-vescalin (18) and the novel vescalene (21) fully inhibited top2 at 10 microM concentration!
Quideau
Stéphane
S
Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac Cedex, France. s.quideau@iecb.u-bordeaux.fr
Jourdes
Michael
M
Lefeuvre
Dorothée
D
Montaudon
Danièle
D
Saucier
Cédric
C
Glories
Yves
Y
Pardon
Patrick
P
Pourquier
Philippe
P
D001713:Biphenyl Compounds / Q000737:chemistry / Q000302:isolation & purification*; D002396:Catechols / Q000737:chemistry / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D006027:Glycosides / Q000737:chemistry*; D006801:Humans; D006868:Hydrolysis; D047348:Hydrolyzable Tannins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry*; D013329:Structure-Activity Relationship; D059005:Topoisomerase II Inhibitors; D014920:Wine
D001713:Biphenyl Compounds; D002396:Catechols; D006027:Glycosides; D047348:Hydrolyzable Tannins; D010636:Phenols; D059005:Topoisomerase II Inhibitors; C084709:vescalagin