Secu’amamines E–G, new alkaloids from Securinega suffruticosa var. amamiensis

One new ent-neosecurinane-type alkaloid, secu’amamine E (1), and two novel alkaloids consisting of a ent-neosecurinane and a piperidine unit, secu’amamine F (2), and secu’amamine G (3), were isolated from Securinega suffruticosa var. amamiensis. Their structures and stereochemistry were elucidated on the basis of spectroscopic analyses.