title: Khellin and Visnagin, Furanochromones from Ammi visnaga (L.) Lam., as Potential Bioherbicides.
abstract: Plants constitute a source of novel phytotoxic compounds to be explored in searching for effective and environmentally safe herbicides. From a previous screening of plant extracts for their phytotoxicity, a dichloromethane extract of Ammi visnaga (L.) Lam. was selected for further study. Phytotoxicity-guided fractionation of this extract yielded two furanochromones, khellin and visnagin, for which herbicidal activity had not been described before. Khellin and visnagin were phytotoxic to model species lettuce (Lactuca sativa) and duckweed (Lemna paucicostata), with IC50values ranging from 110 to 175 μM. These compounds also inhibited the growth and germination of a diverse group of weeds at 0.5 and 1 mM. These weeds included five grasses [ryegrass (Lolium multiflorum), barnyardgrass (Echinocloa crus-galli), crabgrass (Digitaria sanguinalis), foxtail (Setaria italica), and millet (Panicum sp.)] and two broadleaf species [morningglory (Ipomea sp.) and velvetleaf (Abutilon theophrasti)]. During greenhouse studies visnagin was the most active and showed significant contact postemergence herbicidal activity on velvetleaf and crabgrass at 2 kg active ingredient (ai) ha-1. Moreover, its effect at 4 kg ai ha-1was comparable to the bioherbicide pelargonic acid at the same rate. The mode of action of khellin and visnagin was not a light-dependent process. Both compounds caused membrane destabilization, photosynthetic efficiency reduction, inhibition of cell division, and cell death. These results support the potential of visnagin and, possibly, khellin as bioherbicides or lead molecules for the development of new herbicides.
authors.affiliation: Instituto de Biologı́a Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario , Suipacha 531, 2000 Rosario, Argentina.|Investigaciones Biológicas en Agroquímicos Rosario S.A. (INBIOAR S.A.) , Cordoba 1437, Fifth Floor-Office 2, 2000 Rosario, Argentina.
authors.forename: Maria L
authors.identifier: http://orcid.org/0000-0003-3675-5280
authors.initials: ML
authors.lastname: Travaini
authors.affiliation: Investigaciones Biológicas en Agroquímicos Rosario S.A. (INBIOAR S.A.) , Cordoba 1437, Fifth Floor-Office 2, 2000 Rosario, Argentina.
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Sosa
authors.affiliation: Instituto de Biologı́a Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario , Suipacha 531, 2000 Rosario, Argentina.
authors.forename: Eduardo A
authors.identifier: http://orcid.org/0000-0001-5776-3306
authors.initials: EA
authors.lastname: Ceccarelli
authors.affiliation: AgroField Consulting , Gruenstadter Strasse 82, 67283 Obrigheim, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Walter
authors.affiliation: Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture , P.O. Box 1848, University, Mississippi 38677, United States.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Cantrell
authors.affiliation: Instituto de Biologı́a Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario , Suipacha 531, 2000 Rosario, Argentina.
authors.forename: Nestor J
authors.initials: NJ
authors.lastname: Carrillo
authors.affiliation: Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture , P.O. Box 1848, University, Mississippi 38677, United States.
authors.forename: Franck E
authors.identifier: http://orcid.org/0000-0001-6964-2499
authors.initials: FE
authors.lastname: Dayan
authors.affiliation: Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture , P.O. Box 1848, University, Mississippi 38677, United States.
authors.forename: Kumudini M
authors.initials: KM
authors.lastname: Meepagala
authors.affiliation: Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture , P.O. Box 1848, University, Mississippi 38677, United States.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Duke
mesh_terms: D031165:Ammi / Q000737:chemistry*; D001681:Biological Assay; D016923:Cell Death; D002867:Chromones / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D018525:Germination / Q000187:drug effects; D006540:Herbicides / Q000737:chemistry*; D007666:Khellin / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D057685:Plant Weeds / Q000187:drug effects
chemical_list: D002867:Chromones; D005663:Furans; D006540:Herbicides; D010936:Plant Extracts; C477662:furanochromone; D007666:Khellin; C044999:visnagin
keywords: Ammi visnaga; bioherbicide; furanochromone; herbicide; khellin; phytotoxin; visnagin