The invasive plant Eupatorium adenophorum Spreng. (or Ageratina adenophora (Spreng.) King and Robinson) (Compositae) has caused great economic loss in China, especially the southwestern region, and is gravely threatening the native biodiversity. The aerial part of this plant was phytochemically investigated for its allelochemicals. Eleven terpenes (2 monoterpenes and 9 sesquiterpenes) were isolated and identified, which include a new monoterpene, (-)-(1R*,2S,*4R*,5S*)-3,3-dimethyl-5-hydroxybicyclo[2,2,1]hept-2-ylmethanol (1), two new cadinane sesquiterpenes, (-)-(5S*,6S*,7S*,9R*,10S*)-7-hydroxy-5,7-epidioxycadinan-3-ene-2-one (2) and (+)-(5S*,6R*,9R*,10S*)-5,6-dihydroxycadinan-3-ene-2,7-dione (3), and eight known terpene compounds (4, 6-12). The new structures were established by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. Meanwhile, the potential allelopathic effects of these compounds on the Arabidopsis seeds germination were tested. Compounds 3 and 7 retarded the Arabidopsis seeds germination at 0.5 mM and 1.0 mM concentrations, respectively, while other compounds showed no obvious inhibitory effects.
1.Chinese Acad Sci, Kunming Inst Bot, State Key Lab Phytochem & Plant Resources W China, SW China Germplasm Bank Wild Species, Kunming 650204, Peoples R China 2.Dali Coll, Fac Pharm, Dali 671000, Peoples R China 3.Yunnan Univ, Key Lab Conservat & Utilizat Bioresources, Kunming 650091, Peoples R China
Zhao, X; Zheng, GW; Niu, XM; Li, WQ; Wang, FS; Li, SH.Terpenes from Eupatorium adenophorum and Their Allelopathic Effects on Arabidopsis Seeds Germination,JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY,2009,57(2):478-482