title: 7,8-Benzoflavone: a phytotoxin from root exudates of invasive Russian knapweed.
abstract: Root exudates from Acroptilon repens (Russian knapweed) were found to be phytotoxic and the phytotoxin in the exudate was identified as 7,8-benzoflavone (alpha-naphthoflavone), (1), not previously known as a natural product. In tests on growing seedlings both 1 and its isomer 5,6-benzoflavone (2) were phytotoxic. Flavone, a structural analog of 1 and a known granular leaf and stem exudate of other plant species, was also phytotoxic and more potent than 1 or 2.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. frslab@lamar.colostate.edu
authors.forename: Frank R
authors.initials: FR
authors.lastname: Stermitz
authors.forename: Harsh Pal
authors.initials: HP
authors.lastname: Bais
authors.forename: Tommaso A
authors.initials: TA
authors.lastname: Foderaro
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Vivanco
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D001571:Benzoflavones / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D016923:Cell Death / Q000187:drug effects; D031179:Centaurea / Q000737:chemistry* / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D005419:Flavonoids / Q000302:isolation & purification / Q000633:toxicity; D007536:Isomerism; D017440:Photoperiod; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development; D018547:Plant Stems / Q000737:chemistry; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D019324:beta-Naphthoflavone / Q000302:isolation & purification / Q000633:toxicity
chemical_list: D001571:Benzoflavones; D005419:Flavonoids; D010936:Plant Extracts; C011512:alpha-naphthoflavone; D019324:beta-Naphthoflavone