Cytotoxic diarylheptanoids from the pericarps of walnuts (Juglans regia).

Two new diarylheptanoids, juglanin A (1) and B (2), together with 15 known compounds, were isolated from the extract of the seed husks of walnuts (Juglans regia L.). The structures of 1 and 2 were elucidated by various spectroscopic methods including intensive 2D-NMR techniques, HR-ESI-MS, and X-ray single-crystal diffraction analysis, and the cytotoxic activities of 1, 2, and 10 against human hepatoma (Hep G2) cells was reported.