TP53 and hepatocellular carcinoma: Resveratrol tetramers: Vaticanol C (33), kobophenol A (34) and hopeaphenol (35) from Vitis vinifera, a dimer, trans-ε-viniferin (33), as well as two tetramers, R2-viniferin (34) and r-viniferin (35) were obtained and evaluated for their cytotoxic activity to human hepatocellular carcinoma (HCC) cell lines p53 wild-type HepG2 and p53-null Hep3B.