title: Pyrrolizidine alkaloids from Ageratum houstonianum Mill.
abstract: Four pyrrolizidine alkaloids (PA) were isolated from Ageratum houstonianum and their structures elucidated by spectroscopical methods. Besides the already known lycopsamine three new PA were found. Their structures are the 2S-2-hydroxy-2,3-dimethyl-butanoyl-O(9) as well as the O(7) esters of retronecine and the O(9) derivative of heliotridine.
authors.affiliation: Pharmazeutisches Institut der Universität, Universität Bonn, An der Immenburg 4, D-53121, Bonn, Germany. wiedenfeld@uni-bonn.de
authors.forename: H
authors.initials: H
authors.lastname: Wiedenfeld
authors.forename: A
authors.initials: A
authors.lastname: Andrade-Cetto
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D018514:Plant Structures / Q000737:chemistry; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D011763:Pyrrolizidine Alkaloids