Resveratrol is a potent phenolic antioxidant found in natural sources that has antiproliferative activity. When the three phenolic hydroxyl groups of resveratrol are converted to methyl ethers, the inhibition of cell growth is enhanced. 3,4',5-Trismethoxybenzophenone is an analog of trismethoxy resveratrol. It inhibits the growth of a variety of human tumor cell lines at concentrations from 0.4 to 2 µg/ml, which is 5-6 times more potent than resveratrol.