Cytotoxic resveratrol oligomers from the tree bark of Dipterocarpus hasseltii

A new resveratrol tetramer, named diptoindonesin E, was isolated from the acetone extract of the tree bark of Dipterocarpus hasseltii, together with five known resveratrol oligomers (−)-ε-viniferin, laevifonol, (−)-α-viniferin, vaticanol B, (−)-hopeaphenol, and a coumarin, scopoletin. The structures of these compounds were determined from spectroscopic evidence. Cytotoxicity test of the isolated compounds showed that hopeaphenol strongly inhibited murine leukemia P-388 cells.