title: Ancistroguineines A and B as well as ancistrotectorine-naphthylisoquinoline alkaloids from Ancistrocladus guineënsis.
abstract: The isolation of three naphthylisoquinoline alkaloids from the leaves of Ancistrocladus guineënsis is described. Their complete structures were established by spectroscopic, chiroptical and degradative methods. Thus, two hitherto unknown 5,8'-coupled naphthylisoquinoline, named ancistroguineines A and B, were isolated, constituting the first example of a pair of 3-epimeric naphthylisoquinoline alkaloids. Moreover, ancistrotectorine, a 7,3'-coupled alkaloid previously known only from the South-East Asian species Ancistrocladus tectorius, was isolated. Its absolute stereostructure was confirmed by oxidative degradation and by comparison of experimental and calculated CD spectra.
authors.affiliation: Institut für Organische Chemie der Universität, Würzburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Bringmann
authors.forename: C
authors.initials: C
authors.lastname: Günther
authors.forename: S
authors.initials: S
authors.lastname: Busemann
authors.forename: M
authors.initials: M
authors.lastname: Schäffer
authors.forename: J D
authors.initials: JD
authors.lastname: Olowokudejo
authors.forename: B I
authors.initials: BI
authors.lastname: Alo
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D002942:Circular Dichroism; D008401:Gas Chromatography-Mass Spectrometry; D007546:Isoquinolines / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D007546:Isoquinolines; C110300:ancistroguineine A