Centaurea solstitialis

Hamburger M, Wolfender J-L, Hostettmann K (1993) Search for Chlorinated Sesquiterpene Lactones in the Neurotoxic Thistle Centaurea solstitialis by Liquid Chromatographic-Mass Spectrometry, and Model Studies on Their Possible Artifactual Formation. Nat Tox 1 315... 

Both eupatoriochromene and encecalin (9), from yellow starthistle (Centaurea solstitialis L., Asteraceae), retard seed germination and reduce radicle and hypocotyl growth of weed and crop plant seedlings (Merrill, 1989). 

Merrill, G. B., Eupatoriochromene and encecalin, plant growth regulators from yellow starthistle Centaurea solstitialis), J. Chem. Ecol., 15, 2073-2087 (1989). 

In one of the original papers of the Vivanco laboratory [46], the mechanism of action of (-)-catechin was linked to induction of ROS. This is debatable since catechins are well known antioxidants (e.g. [62]). In fact, more than 1500 papers mention catechin as an antioxidant (SciFinder search, as of February 2008). Finally, Qin et al. [63] found no evidence of root exudate-mediated allelopathy with Centaurea solstitialis, but the authors apparently did not determine if this species produces ( )-catechin. If it were to produce similar amounts of ( )-catechin as C. maculosa, it would be strong evidence of the lack of allelo-pathic influence of these compounds. 

Qin, B. et al. (2007) No evidence for root-mediated allelopathy in Centaurea solstitialis, a species in a commonly allelopathic genus. Biolog. Invasions 9, 897-907... 

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