Determination of Stilbenes (δ-viniferin, trans-astringin, trans-piceid, cis- and trans-resveratrol, ε-viniferin) in Brazilian Wines

Abstract

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to protect lipoproteins from oxidative damage and to have cancer chemopreventive activity. We describe a method for the direct determination of stilbenes in several red wines using high-performance liquid chromatography with UV detection. In a survey of 12 commercial wines from the south of Brazil (Rio Grande del Sul), levels of delta-viniferin are reported for the first time in different varieties of red wines. Brazilian red wine contains trans-astringin, trans-piceid, trans-resveratrol, cis-resveratrol (in high quantity: 5 times more than the trans form), epsilon-viniferin, and a compound isolated for the first time in wine, trans-delta-viniferin. Isolation and identification of delta-viniferin was achieved by NMR after extraction and fractionation of red wine phenolics. delta-Viniferin contributes, as well as cis-resveratrol and trans-piceid, to a significant proportion of stilbenes in wine dietary intake, particularly with Merlot varieties containing an average level of 10 mg/L for delta-viniferin, 15 mg/L for cis-resveratrol, and 13 mg/L for trans-piceid. The total stilbene intake from wine origin was estimated for the Brazilian population as 5.3 mg/day per person (on the basis of a regular wine consumption of 160 mL/day). delta-Viniferin can contribute to around 20% of total stilbenes in wine (average of 6.4 mg/L in red Brazilian wines). It would be important in the future to investigate the origins of the differences in wine stilbene levels in relation to the vine varieties, and the bioavailability of the newly extracted stilbene delta-viniferin in plasma after consumption of different types of wines.

Wine and grape polyphenols—A chemical perspective

“…ε-viniferin, Fig. 7) were also identified in grapevine leaves and wine by-products (Jiang et al, 2010;Lima et al, 1999;Moreno-Labanda et al, 2004;Pezet et al, 2003;Püssa et al, 2006;Vitrac et al, 2005).…”

Wine and grape polyphenols — A chemical perspective

“…ε-viniferin, Fig. 7) were also identified in grapevine leaves and wine by-products (Jiang et al, 2010;Lima et al, 1999;Moreno-Labanda et al, 2004;Pezet et al, 2003;Püssa et al, 2006;Vitrac et al, 2005).…”

Resveratrol content and antioxidant properties of underutilized fruits

“…Resveratrol occurs in both cis and trans isomeric forms. Cis-resveratrol has not been reported in V. vinifera however, it has been shown to be present in wines (Vitrac et al 2005). All of the research investigations focused only upon the trans-isomer, due to the unstability of cis-isomer and of the fact that it is not available commercially.…”