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.