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Grapevine canes are rich in resveratrol and its complex derivatives. These compounds have many biological activities and are needed mainly for health purposes. Canes, which are often wasted, can be used to produce these high-value compounds at low cost. We studied sixteen Vitis vinifera L. cultivars among the most widely cultivated ones worldwide. Polyphenols were extracted from their canes and identified by liquid chromatography-nuclear magnetic resonance spectroscopy. We accurately determined the content of E-ε-viniferin, E-resveratrol, E-piceatannol, and vitisin B and, for the first time, that of hopeaphenol and miyabenol C. The canes did not contain these major stilbene compounds in similar proportions, and their abundance and order of abundance varied according to the cultivar. For instance, Pinot noir has very high levels of E-resveratrol and E-ε-viniferin; Gewurztraminer has very high levels of vitisin B, and Carignan and Riesling have very high levels of hopeaphenol. These findings suggest that the right cultivar should be used to obtain the highest yield of a polyphenol of interest.

Stilbenes have been shown to have cancer chemopreventive activity and to protect lipoproteins from oxidative damage. A method is described for their direct determination in different types of wine using high-performance liquid chromatography with ultraviolet detection. In a survey of 120 commercial wines from Portugal and France, the highest concentrations of stilbenes were found in red wines. The glucosides of resveratrol were present in higher concentrations than the free isomers. Isolation from wine and characterization of trans-astringin in a large quantity are described for the first time.

Stilbene-enriched extracts from Vitis vinifera waste (cane, wood, and root) were characterized by UHPLC-MS. Eleven stilbenes were identified and quantified as follows: ampelopsin A, (E)-piceatannol, pallidol, (E)-resveratrol, hopeaphenol, isohopeaphenol, (E)-ε-viniferin, (E)-miyabenol C, (E)-ω-viniferin, r2-viniferin, and r-viniferin. The fungicide concentration inhibiting 50% of growth of Plasmopara viticola sporulation (IC) was determined for the extracts and also for the main compounds isolated. r-Viniferin followed by hopeaphenol and r2-viniferin showed low IC and thus high efficacy against Plasmopara viticola. Regarding stilbene extracts, wood extract followed by root extract showed the highest antifungal activities. These data suggest that stilbene complex mixtures from Vitis vinifera waste could be used as a cheap source of bioactive stilbenes for the development of natural fungicides.

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The interaction between Vitis vinifera and trunk disease fungi requires better understanding. We studied the role of phenolics as possible plant defense compounds in this context. The impact of 24 grapevine phenolic compounds was determined on 6 major wood decay fungi by an in vitro agar plate assay. Hydroxystilbenoids, especially oligomers such as miyabenol C, isohopeaphenol, and vitisin A and B, greatly reduced the growth of the fungi, except that of Phaeoacremonium aleophilum . A detailed investigation in 10 Botryosphaeriaceae strains revealed that all of the studied members of this family display a common susceptibility to phenolics that is more or less significant. Then we undertook a quantitative analysis of stilbenoid content in grapevine plantlets inoculated with Botryosphaeriaceae to investigate whether in planta these fungi have to counteract the most active phenolics. On the basis of our results, the possible role of phenolics in grapevine defense against trunk disease agents is discussed.

We present stilbenoid profiles of canes from 16 grapevines. Fifteen stilbenoids were obtained through isolation and structure identification using MS, NMR, and [α](D) or as commercial standards. An HPLC-UV method for the simultaneous quantification of nine of these stilbenoids was developed and applied to canes of Vitis amurensis, Vitis arizonica, Vitis berlandieri, Vitis betulifolia, Vitis cinerea, Vitis × champini, Vitis × doaniana, Vitis labrusca, Vitis candicans (syn. Vitis mustangensis), Vitis riparia, Vitis rupestris, Vitis vinifera, Muscadinia rotundifolia, and a V. vinifera × M. rotundifolia hybrid. In these species, E-ampelopsin E, E-amurensin B, E-piceid, E-piceatannol, E-resveratrol, E-resveratroloside, E-ε-viniferin, E-ω-viniferin, and E-vitisin B were quantified, when found in sufficient amounts. Total concentrations ranged from ~2.2 to 19.5 g/kg of dry weight. Additional stilbenoids, E-3,5,4'-trihydroxystilbene 2-C-glucoside, Z-ampelopsin E, Z-trans-miyabenol C, E-trans-miyabenol C, scirpusin A, and Z-vitisin B, were identified but not quantified. Our results indicate that canes, particularly those of non-vinifera species, have substantial quantities of valuable, health-promoting stilbenoids.