Abstract:
Six new stemofoline alkaloids, (2`R)-hydroxystemofoline (5), (3`R)-stemofolenol (6), (3`S)-stemofolenol (7), 1`,2`-didehydrostemofoline-N-oxide (8), the first C19 stemofoline alkaloid, methylstemofoline (9), and the first glycosidated Stemona alkaloid, stemofolinoside (10), and three known alkaloids, (2`S)-hydroxystemofoline (2), (11Z)-1`,2`-didehydrostemofoline (3), and (11E)-1`,2`-didehydrostemofoline (4), have been isolated from a root extract of an unidentified Stemona species. The structure and relative configuration of these new alkaloids have been determined by spectral data interpretation and from semisynthetic studies.
