Idiospermuline, a trimeric pyrrolidinoindoline alkaloid from the seed of Idiospermum australiense.

Purification of a methanol extract from the seed of Idiospermum australiense, guided by bioactivity on a rat brain cortical wedge preparation has afforded two known dimeric alkaloids, the piperidinoindoline (+)-calycanthine [1] and the pyrrolidinoindoline, (-)-chimonanthine [2] along with a new trimeric pyrrolidinoindoline alkaloid, (-)-idiospermuline [3]. Te structure of idiospermuline [3] was determined by spectroscopic methods and the absolute configuration by an X-ray crystallographic study of idiospermuline trimethiodide [4].