δ-Viniferin, a Resveratrol Dehydrodimer: One of the Major Stilbenes Synthesized by Stressed Grapevine Leaves

摘要: Delta-viniferin is a resveratrol dehydrodimer, an isomer of epsilon-viniferin. This compound has been reported as molecule produced in vitro by the oxidative dimerization plant peroxidases or fungal laccases. It was also recently identified wines and grape cell cultures. We have now this dimer NMR, high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (MS) grapevine leaves infected Plasmopara viticola (downy mildew) UV-C irradiated. Its concentration higher than that epsilon-viniferin constitutes one most important phytoalexins derived from resveratrol.