A new cytotoxic amide from the stem wood of Hibiscus tiliaceus

A new coumarin, hibiscusin, and a new amide, hibiscusamide, together with eleven known compounds including vanillic acid, p-hydroxybenzoic acid, syringic acid, p-hydroxybenzaldehyde, scopoletin, N-trans-feruloyltyramine, N-cis-feruloyltyramine, a mixture of β-sitosterol and stigmasterol, a mixture of /3-sitostenone and stigmasta-4,22-dien-3-one were isolated from the stem wood of Hibiscus tiliaceus. The structures of these new compounds were determined through spectral analyses. Among the isolates, three compounds exhibited cytotoxicity (IC 50 values < 4μg/mL) against P-388 and/or HT-29 cell lines in vitro.