Daphmanidins C and D, novel pentacyclic alkaloids from Daphniphyllum teijsmanii

Two novel alkaloids with an unprecedented fused-pentacyclic skeleton, daphmanidins C (1) and D (2), have been isolated from the leaves of Daphniphyllum teijsmanii, and the structures were elucidated on the basis of spectroscopic data. The relative stereochemistry of I and 2 was assigned by combination of NOESY correlations and a simulation analysis. Daphmanidin C (1) elevated activity of NGF biosynthesis.