title: Phytotoxic activity of flavonoids from Dicranostyles ampla.
abstract: Crude extracts from over 16 species of plants from the family Convolvulaceae were evaluated for phytotoxic activity against Agrostis stolonifera (bentgrass) and Lactuca sativa (lettuce) at 1000 microg/mL. Ethanol extracts of Dicranostyles ampla Ducke were among the most active of those species tested. Systematic bioassay-guided fractionation of the ethanol extract of the aerial parts from this species was performed to identify specifically the phytotoxic compounds. Two phytotoxic flavonoids, dihydromyricetin (1) and myricetin-3-O-alpha-rhamnoside or myricetrin (2), were found to be responsible for much of the activity of the extract as a whole in the A. stolonifera and L. sativa bioassay. In a Lemna paucicostata bioassay, 1 and 2 had no activity at 100 microM.
authors.affiliation: IQAC-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain. amaya.castro@iqac.csic.es
authors.forename: Amaya
authors.initials: A
authors.lastname: Castro
authors.forename: Charles L
authors.initials: CL
authors.lastname: Cantrell
authors.forename: Amber L
authors.initials: AL
authors.lastname: Hale
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Duke
mesh_terms: D031703:Agrostis / Q000187:drug effects*; D027722:Convolvulaceae / Q000737:chemistry*; D005419:Flavonoids / Q000633:toxicity*; D018545:Lactuca / Q000187:drug effects*; D010936:Plant Extracts / Q000633:toxicity*
chemical_list: D005419:Flavonoids; D010936:Plant Extracts