Alkaloids from Melodinus suaveolens

Two new quinoline alkaloids, 14,15-beta-epoxyscandine (3) and meloscine N-oxide (6), along with six known alkaloids scandine (1), scandine N-oxide (2), meloscandonine (4), meloscine (5), tubotaiwine (7), polyneuridine (8) were isolated from the twigs and leaves of Melodinus suaveolens. The structures of the new compounds were elucidated on the basis of spectroscopic methods and circular dichroism experiments.