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Stilbenoids have received increasing attention over the last two decades since the discovery of resveratrol in wine. With an ever-growing rhythm, a multitude of biological activities of naturally occurring stilbenes are being reported. In this work, we investigated minor stilbenoid compounds from Vitis vinifera stalks. The compounds were purified by means of centrifugal partition chromatography (CPC), a countercurrent-separation technique. Electrospray ionization–ion trap mass spectrometry (ESI–IT-MS) after optimization proved to be extremely efficient for the detection of these new molecules, providing both structural information for structure elucidation and a means to achieve identification even with minute amounts. Here a new stereoisomer of E -miyabenol C, E - cis - cis -miyabenol C ( 2 ), along with the already reported E - trans - cis -miyabenol C ( 1 ) and E - cis - trans -miyabenol C ( 3 ), was purified from a complex Vitis vinifera cane extract, using adapted solvent systems K and L from the ‘Arizona’ solvent system range, without the need for any solid support. Moreover, compounds 1 – 3 showed an inhibitory activity on α-synuclein filament formation. [ABSTRACT FROM AUTHOR]

The polyphenols, for example stilbenes and flavonoids, are an important family of compounds present in grapes and wines. Several studies have shown that stilbenes are antioxidants and cancer-preventing agents. For the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)- trans-ε-viniferin, pallidol, and hopeaphenol), isolated and purified from Vitis vinifera, were simultaneously analysed by ultra-high-pressure liquid chromatography coupled with photodiode-array detection. Separation of the stilbenes by UHPLC was optimized with the assistance of 'Quality-by-Design' commercial software. Four different reversed-phase columns packed with 1.5-1.7-μm particles were tested and compared for their retention behaviour and separation efficiency. On the basis of the performance characteristics determined, the VisionHT C18 HL column was selected for the stilbenes studied, because resolution of the critical pair was 1.5 with a peak width of 2-4 s. The optimized method resulted in highly repeatable retention times (RSD 0.03-0.07%), peak areas (RSD 3-6%), and linear ranges were between 0.005 and 50 mg L for most of the compounds. All stilbenes, except trans-astringin, trans-piceatannol, and pallidol were identified and quantified in Burgundy red wines at different concentrations after direct injection of the wines. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Twenty stilbene derivatives and moracin M extracted from natural products were tested against amyloid-β peptide (Aβ) aggregation. Results of stilbene monomer derivatives indicated that interaction with resveratrol and piceid was specific. Concerning oligomers, scirpusin A and ε-viniferin glucoside demonstrated a strong inhibition of the aggregation process. [Copyright &y& Elsevier]