Six new alkaloids from Melodinus henryi.

A total of six new alkaloids, melodinhenines A-F (1-6), were isolated from Melodinus henryi. Melodinhenines A and B are new eburnan-vindolinine-type bisindole alkaloids and melodinhenines C-F are new quinolinic melodinus alkaloids. Their structures were elucidated through extensive spectroscopic methods including 2D NMR and HRESIMS analyses. The absolute configuration of 1 and 2 was determined using ECD exciton chirality method. To the best of our knowledge, this is the first report on the determination of the absolute configuration of eburnan-vindolinine-type bisindole alkaloid using this method.