Daphmacrodins A and B, alkaloids from Daphniphyllum macropodum

Two new daphnicyclidin-type Daphniphyllum alkaloids, daphmacrodins A and B (1 and 2) were isolated from the leaves and stems of Daphniphyllum macropodum. Their structures were elucidated by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry. The relative configuration of 1 was further confirmed by a single-crystal X-ray diffraction analysis. Their cytotoxic activities against five human cancer cell lines, pesticidal activities against brine shrimp (Artemia salina), and antibacterial activities against five standard bacterial and fungal strains were evaluated. The structure of 1 was successfully transformed to 2 by a chemical method.