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.
Two new alkaloids, fluevirines E (1) and F (2), along with six known Securinega alkaloids, were isolated from the methanol extract of the twigs and leaves of Flueggea virosa. The structures and absolute configurations of the new compounds were elucidated by means of MS, NMR, and ECD analyses. Compound 1 is a new dimeric indole alkaloid while 2 is a new securinega-type alkaloid. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines and their acetylcholinesterase inhibitory activity were also evaluated. Graphical Abstract