Phytotoxic compounds from roots of Centaurea diffusa Lam.
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.
Quintana
Naira
N
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA. j.vivanco@colostate.edu
El Kassis
Elie G
EG
Stermitz
Frank R
FR
Vivanco
Jorge M
JM
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
D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D045788:Sesquiterpenes, Germacrane; D015125:Oxyquinoline; D019787:Linoleic Acid; C515179:caryophyllene oxide