Daphniphyllum alkaloids

Abstract

The unique polycyclic fused ring systems of Daphniphyllum alkaloids, along with their extensive bioactivities, make this family of alkaloids especially attractive targets for total synthesis and biogenetic studies. In particular, successive discoveries of new alkaloids with unprecedented skeletons in recent years have made great contribution to structural diversities of alkaloids elaborated by plants of the genus Daphniphyllum. By the end of 2008, more than 200 alkaloids belonging to 14 different skeletal types have been isolated from different parts of plants of thirteen Daphniphyllum species. These alkaloids show cytotoxic, antioxidant, vasorelaxant and anti-platelet activating factor (PAF) effects. The plausible biosynthetic pathways for Daphniphyllum alkaloids have been proposed and biomimetic total syntheses of some alkaloids completed. To provide an update of the previous reviews published in 2009, chemical structures, biosynthesis, syntheses and pharmacological activities of Daphniphyllum alkaloids reported in the latest years are presented in this chapter. Between 2009 and 2012, additional fifty-one novel alkaloids have been isolated and identified. Among them, some possess unprecedented frameworks. Several state -of-the-art total syntheses through cascade reactions were completed.