Allelochemicals from sunflower leaves cv. Peredovick

Isolation, structural elucidation and allelopathic bioassays of 13 compound s, isolated from sunflower cultivar cv. Peredovick are described. Two new s esquiterpene lactones, helivypolide D and helivypolide E and the bisnorsesq uiterpene, annuionone D, which is reported at the first time as natural pro duct, are described. The effects of a series of aqueous solutions at 10(-4) -10(-9) M of these compounds were studied on the root and shoot lengths of Lactuca sativa, Lepidium sativum seedlings (dicotyledons) and Hordeum vulga re and Allium cepa (monocotyledons), (C) 1999 Elsevier Science Ltd. All rig hts reserved.