title: Furanonaphthoquinones, atraric acid and a benzofuran from the stem barks of Newbouldia laevis.
abstract: The series of naturally occurring furanonaphthoquinones is extended by identification of the derivatives 2-(1'-methylethenyl)-5-hydroxynaphtho[2,3-b]furan-4,9-dione and 2-(1'-methylethenyl)-7-hydroxynaphtho[2,3-b]furan-4,9-dione. They are accompanied in the stem barks of Newbouldia laevis by the known analogues 5-hydroxy-dehydro-iso-alpha-lapachone, 2-acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dione and 2-(1'-methylethenyl)naphtho[2,3-b]furan-4,9-dione along with the rare atraric acid and the new 2-(1'-methylethenyl)-6-hydroxy-2,3-dihydrobenzofuran. The structures of these compounds were established from spectroscopic studies.
authors.affiliation: Institut für Pharmazie, Freie Universität Berlin, D-14195 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Gormann
authors.forename: Maki
authors.initials: M
authors.lastname: Kaloga
authors.forename: Xing-Cong
authors.initials: XC
authors.lastname: Li
authors.forename: Daneel
authors.initials: D
authors.lastname: Ferreira
authors.forename: Dieter
authors.initials: D
authors.lastname: Bergenthal
authors.forename: Herbert
authors.initials: H
authors.lastname: Kolodziej
mesh_terms: D001572:Benzofurans / Q000737:chemistry / Q000302:isolation & purification*; D029402:Bignoniaceae / Q000737:chemistry*; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification*; D062385:Hydroxybenzoates / Q000737:chemistry / Q000302:isolation & purification*; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D001572:Benzofurans; D005663:Furans; D062385:Hydroxybenzoates; D009285:Naphthoquinones; C480398:atraric acid