Four new lignans from Viburnum foetidum var. foedidum.

The 70% aqueous acetone extract of the aerial part of Viburnum foetidum var. foedidum afforded four new lignans (1-4) together with six known ones. The structures of the four new compounds were elucidated on the basis of 1D (dimensional), 2D-NMR, and mass spectral analysis. The structure of compound 1, with a novel spirocyclic moiety, was also confirmed by X-ray diffraction analysis. Compounds 1-10 were evaluated for their cytotoxic activity. However, none of the compounds showed significant cytotoxic activity.