5-[(1E)-2-(4-Hydroxyphenyl)ethenyl]-2-(phenylmethyl)-1,3-benzenediol

5-[(1E)-2-(4-Hydroxyphenyl)ethenyl]-2-(phenylmethyl)-1,3-benzenediol is the impurity B of Resveratrol (R150000); a minor constituent of wine, correlated with serum lipid reduction and inhibition of platelet aggregation. Resveratrol is a specific inhibitor of COX-1 and also inhibits the hydroperoxidase activity of COX-1. It has been shown to inhibit events associated with tumor initiation, promotion and progression.