title: Indole Alkaloids from Alstonia angustifolia.
abstract: From the stem bark of ALSTONIA ANGUSTIFOLIA, eleven alkaloids were isolated. Seven of them are known ones: echitamine ( 1), N(b)-demethylechitamine ( 2), pseudoakuammigine ( 3), tubotaiwine ( 5), akuammicine ( 6), N(b)-beta-methylantirhine ( 12), and N(b)-methylakuammidine ( 13). The four others, pseudoakuammigine N-oxide ( 4), akuammicine N-oxide ( 7), N(b)-demethylalstogustine ( 8), and N(b)-demethylalstogustine N-oxide ( 11), are new alkaloids. Their structures were determined by means of spectroscopic analysis and chemical correlation with known alkaloids.
authors.affiliation: Organisch-chemisches Institut der Universität Zürich, Winterthurerstraße 190, CH-8057 Zürich, Switzerland.
authors.forename: W L
authors.initials: WL
authors.lastname: Hu
authors.forename: J P
authors.initials: JP
authors.lastname: Zhu
authors.forename: M
authors.initials: M
authors.lastname: Hesse