Alstorisine A, a nor-Monoterpenoid Indole Alkaloid from Cecidogenous Leaves of Alstonia scholaris.

Abstract Alstorisine A (1), a novel nor-monoterpenoid indole alkaloid with 6/5/6/6 fused-ring system, regarded as a key intermediate from melodinine E to mersicarpine, was isolated from the cecidogenous leaves of Alstonia scholaris. Its structure was identified on the basis of extensive spectroscopic analysis and the comparison of experimental and calculated ECDs. A plausible biogenesis was also postulated.