Resveratrol and two monomethylated stilbenes from Israeli Rumex bucephalophorus and their antioxidant potential.

The roots of Rumex bucephalophorus were analyzed for resveratrol and analogues. Two stilbene-O-methyl derivatives were identified, in addition to resveratrol (3,5,4'-trihydroxystilbene). The stilbene-O-methyl derivatives were shown to be 5,4'-dihydroxy-3-methoxystilbene and 3,5-dihydroxy-4'-methoxystilbene. The antioxidant capacities of all these stilbenes were determined.