Δ-Viniferin
δ-Viniferin is a resveratrol dehydrodimer. It is an isomer of epsilon-viniferin. It can be isolated from stressed grapevine leaves. It is also found in plant cell cultures and wine. It can also be found in Rheum maximowiczii.
It is a grapevine phytoalexin following stresses like Fungal [infection in plants|fungal infection], UV light irradiation or ozone treatment.
Botryosphaeria obtusa, a pathogen responsible for the black dead arm disease of grapevine, has also been shown to be able to oxidise wood δ-resveratrol into delta-viniferin.
In cell cultures, the use of methyl jasmonate and jasmonic acid as elicitors stimulates δ-viniferin biosynthesis.
Delta-viniferin can also be produced from resveratrol by human PTGS1 or from trans-resveratrol and -epsilon-viniferin by horseradish peroxidase.