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.
