Allelopathic activity of luteolin 7-O-β-glucuronide isolated from Chrysanthemum morifolium L.

Two flavones, luteolin 7-O-beta-glucuronide and diosmetin 7-O-beta-glucuronide, were isolated and identified from Chrysanthemum morifolium L. v. Ramat leaves. Identification techniques included HPLC DAD, MS, H-1 and C-13 NMR spectroscopy. At concentrations of 0.2 and 2.0 mM, luteolin 7-O-beta-glucuronide significantly reduced the frond number and chlorophyll content of Lemna gibba plants, but did not significantly affect dry weight. At a concentration of 0.2 mM diosmetin 7-O-beta-glucuronide had no significant effect on frond number, dry weight or chlorophyll concentration of L. gibba. These results indicate that an ortho-3',4'-dihydroxy arrangement of the B-flavonoid ring in the luteolin compound is probably responsible for allelopathic activity. (C) 2004 Elsevier Ltd. All rights reserved.