Neolignan and phenylpropanoid compounds from the resin of Styrax tonkinensis .

A new neolignan compound, tonkinensisin A (1), and two phenylpropanoid compounds, tonkinensisin B (2) and tonkinensisin C (3), were isolated from the resin of Styrax tonkinensis (Pierre) Craib ex Hartw. The structures of these compounds were determined by spectroscopic analysis, and the relative configurations of compounds 1 and 3 were determined by J-based configuration analysis (JBCA) method. All compounds were assayed for cytotoxic activities against five tumor cell lines (HepG-2, A549, Hela, MCF-7, and PC-3) by CCK-8 test in vitro.