Further Daphniphyllum alkaloids from the bark of Daphniphyllum macropodum Miq.

Four new Daphniphyllum alkaloids, namely dehydroxymacropodumine A (1), 4,21-deacetyl-23-demethyl-deoxyyuzurimine (2), 7-oxo-deoxyyuzurimine (3), and 4-acetoxydaphmanidin B (4), together with seven known related alkaloids, were isolated from the bark of Daphniphyllum macropodum Miq. The structures of new compounds 1-4 including relative configurations were elucidated on the basis of detailed spectroscopic data analysis and by comparison with related known compounds. Dehydroxymacropodumine A (1) possesses a rare eleven-membered macrolactone ring representing the second example of this backbone isolated from natural sources.