Psychollatine, a glucosidic monoterpene indole alkaloid from Psychotria umbellata

A monoterpene indole alkaloid, psychollatine (1), was isolated from Psychotria umbellata leaves. Its structure was characterized by interpretation of spectroscopic data and by comparison of its NMR data with those of croceaine A (2) from Palicourea crocea. The configuration of psychollatine (1) was established by NOE difference and circular dichroism (CD) techniques, while its conformation was evaluated through molecular modeling studies and NMR coupling constants.