title: Uredinorubellins and caeruleoramularin, photodynamically active anthraquinone derivatives produced by two species of the genus ramularia.
abstract: Both the phytopathogenic fungus Ramularia collo-cygni and the hyperparasite R. uredinicola biosynthesize a number of red and yellow anthraquinone derivatives called rubellins. The new compounds uredinorubellins I and II, which were isolated from R. uredinicola, contribute to understanding the biosynthesis pathway that leads from simple anthraquinones to the rubellins. In addition, we isolated for the first time such simple compounds as chrysophanol and helminthsporin from both Ramularia species. A blue compound isolated from the mycelium of R. collo-cygni was revealed to be a unique 9,4-anthracenedione derivative. Structure elucidation by (1)H and (13)C NMR of the new but unstable compound caeruleoramularin was possible only by feeding the fungus different labeled (13)C acetates. The photodynamic activity of the uredinorubellins was comparable to rubellin D, whereas chrysophanol and caeruleoramularin did not display such activity.
authors.affiliation: Institute of Pharmacy, University of Jena, Neugasse 23, Jena D-07743, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Miethbauer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Günther
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Schmidtke
authors.forename: Ingrid
authors.initials: I
authors.lastname: Heiser
authors.forename: Susanna
authors.initials: S
authors.lastname: Gräfe
authors.forename: Burkhard
authors.initials: B
authors.lastname: Gitter
authors.forename: Bernd
authors.initials: B
authors.lastname: Liebermann
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001203:Ascomycota / Q000145:classification / Q000378:metabolism*; D002018:Bufanolides / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000880:Anthraquinones; D002018:Bufanolides; C533327:caeruleoramularin; C525200:rubellin