Centrifugal partition chromatography followed by HPLC for the isolation of cis-ε-viniferin, a resveratrol dimer newly extracted from a red Algerian wine

Grapes and related products are considered the major dietary sources of stilbenes. Among these compounds, trans-resveratrol is one of the most important in terms of biological activity, since it has been reported to prevent or to slow the progression of a wide variety of illnesses. We report for the first time the isolation and structure elucidation of cis-ε-viniferin, a biologically active resveratrol dihydrodimer from a red Algerian wine. The Merlot wine was fractionated by column chromatography followed by centrifugal partition chromatography (CPC) and then by reverse-phase semi-preparative HPLC. The structure of cis-ε-viniferin was elucidated by means of 1H NMR and 2D correlations. Cis-ε-viniferin concentrations were determined in wine samples originating from North Africa, most of which are commercially available in France. Stilbene quantification was based on an HPLC method with diode array detection. Unlike trans-ε-viniferin, cis-ε-viniferin was present in almost all wine samples studied and the concentrations ranged from 0.10 to 1.12 mg/l.