The Daphniphyllum Alkaloids with A New Nitrogen Heterocyclic Skeleton

Abstract

Abstract The isolation and structures of six new alkaloids [yuzurine, daphnigracine, daphnigraciline, oxodaphnigracine, oxodaphnigraciline, and epioxodaphnigraciline] are described. The structure of yuzurine, which has been elucidated by means of an X-ray crystallographic analysis of the corresponding methiodide, is in full agreement with its spectral data. The structures of the other five alkaloids, all of which were isolated from the plant Daphniphyllum gracile Gage collected in New Guinea, were deduced on the basis of an exhaustive comparison of their spectral data coupled with chemical evidences. Finally, a plausible biogenesis of these alkaloids with a new type of nitrogen heterocyclic skeleton is discussed.