Antioxidant activity and inhibition of alpha-glucosidase by trans-resveratrol, piceid, and a novel trans-stilbene from the roots of Israeli Rumex bucephalophorus L.

The roots of Rumex bucephalophorus, collected in Israel, were analyzed for trans-stilbenes. Two stilbene-O-glycosyl derivatives were identified, in addition to 3,5,4'-trihydroxystilbene (1) (resveratrol). The stilbene-O-glycosyl derivatives were 5,4'-dihydroxystilbene-3-O-beta-d-glucopyranoside (2) (piceid) and the new 5,4'-dihydroxystilbene-3-O-alpha-arabinopyranoside (3), which is being named rumexoid.

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.