Gelsochalotine, a novel indole ring-degraded monoterpenoid indole alkaloid from Gelsemium elegans

A phytochemical investigation of Gelsemium elegans Benth. led to the isolation of a novel alkaloid, gelsochalotine (1), as the first example of an indole ring-degraded monoterpenoid indole alkaloid from the family Loganiaceae. The structure of 1 was elucidated by spectroscopic analysis, and confirmed by single crystal X-ray diffraction. Studies on the biogenetic derivation of 1 were performed and its cytotoxic activities against human cancer cell lines, BEL-7420 and MDA-MD-435 cell, were evaluated with the MTT assay.