Stilbene synthase catalyses the conversion of p-Cumaroyl-CoA to
Resveratrol (3,5,4-trihydroxy-trans-stilbene) belongs to the
flavonoid group of compounds and is classed among the
phytoalexins.Phytoalexins are a class of antibiotic polyphenol
compounds that form part of the plant defence system.
Resveratrol was first identified and isolated from Japanese
knotweed plants, but it is also present in grapevine (Vitis
vinifera), pine, linseed, sesame seed and peanuts. In grapevine the
highest concentration of resveratrol (between 50 and 100 μg/g) is
found in the grape skins.
Resveratrol is a metabolite produced by the plant in response to
stress, for instance, when subjected to high levels of ozone or
ultra violet irradiation, or when under attack by fungi or insects.
Beneficial effects on the human immune system have also been
attributed to resveratrol. This is based mainly on its antioxidant
properties. Resveratrol is primarily a scavenger of peroxy
radicals. It reduces lipoprotein lipid (LDL) peroxidation and
protects cell membranes against the damaging effects of oxidated
LDL. Resveratrol is also thought to have anticarcinogenic and