title: 5'-O-demethyldioncophylline A, a new antimalarial alkaloid from triphyophyllum peltatum.
abstract: From the root bark of Triphyophyllum peltatum, the new naphthylisoquinoline alkaloid 5'-O-demethyldioncophylline A has been isolated. Its otherwise difficult separation from the largely dominating main alkaloid, dioncophylline A, was greatly facilitated by a bromination-benzylation procedure. From the resulting derivative, a crystal structure analysis with an anomalous X-ray diffraction was achieved, allowing confirmation of the full absolute stereostructure of the new alkaloid. The structure was further corroborated by a partial synthesis from dioncopeltine A. The natural product was shown to exhibit antimalarial activity against erythrocytic forms of Plasmodium falciparum.
authors.affiliation: Institut für Organische Chemie der Universität, Am Hubland, D-97074, Würzburg, Germany
authors.forename: Gerhard
authors.initials: G
authors.lastname: Bringmann
authors.forename: Wael
authors.initials: W
authors.lastname: Saeb
authors.forename: Ralf
authors.initials: R
authors.lastname: God
authors.forename: Manuela
authors.initials: M
authors.lastname: Schäffer
authors.forename: Guido
authors.initials: G
authors.lastname: François
authors.forename: Karl
authors.initials: K
authors.lastname: Peters
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Peters
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
authors.lastname: Kurt Hostettmann
authors.forename: Laurent Aké
authors.initials: LA
authors.lastname: Assi