Angustinine--a new benzopyridoquinolizine alkaloid from Alangium lamarckii.

A new benzopyridoquinolizine alkaloid, designated as angustinine (1), was isolated from the root bark of Alangium lamarckii Thwaites, along with the known ipecac alkaloid, emetine. Investigation of the stem bark of the same plant resulted in the isolation of another known ipecac alkaloid, cephaeline. The structure of the new alkaloid (1) was elucidated on the basis of 2D NMR spectralanalysis.