title: Phytotoxic compounds from roots of Centaurea diffusa Lam.
abstract: An extract of roots of Centaurea diffusa (diffuse knapweed) yielded caryophyllene oxide and linoleic acid which were shown to be phytotoxic. Also isolated were germacrene B, a previously-known phytotoxin as well as the inactive polyene aplotaxene. A combination of these compounds, if transferred to the soil, could be one factor in the invasive behavior of this weed. Contrary to a literature report, 8-hydroxyquinoline was not detected in root exudates of in vitro grown C. diffusa nor could it be identified in the root extract. However, a recent report from a different group maintains that 8-hydroxyquinoline can be released from roots of C. diffusa following a diurnal rhythm.
authors: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA. j.vivanco@colostate.edu
authors: Naira
authors: N
authors: Quintana
authors: Elie G
authors: EG
authors: El Kassis
authors: Frank R
authors: FR
authors: Stermitz
authors: Jorge M
authors: JM
authors: Vivanco
mesh_terms: D017360:Arabidopsis / Q000187:drug effects; D031179:Centaurea / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D019787:Linoleic Acid / Q000378:metabolism / Q000633:toxicity; D015125:Oxyquinoline / Q000378:metabolism / Q000633:toxicity; D018517:Plant Roots / Q000378:metabolism*; D000081223:Polycyclic Sesquiterpenes; D036226:Seedlings / Q000187:drug effects; D012717:Sesquiterpenes / Q000378:metabolism / Q000633:toxicity; D045788:Sesquiterpenes, Germacrane / Q000378:metabolism / Q000633:toxicity
chemical_list: D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D045788:Sesquiterpenes, Germacrane; D015125:Oxyquinoline; D019787:Linoleic Acid; C515179:caryophyllene oxide