title: The use of bio-guided fractionation to explore the use of leftover biomass in Dutch flower bulb production as allelochemicals against weeds.
abstract: A major problem in flower bulb cultivation is weed control. Synthetic herbicides are mainly used, although they cause a range of problems, and integrated weed control through application of naturally occurring allelochemicals would be highly desirable. Flower bulb production creates large amounts of leftover biomass. Utilizing this source for weed control may provide new applications of the bulb crops. We therefore screened 33 flower bulb extracts for allelochemical activity against weeds. Several methanol and chloroform extracts were observed to inhibit germination and growth of Senecio vulgaris L. and Lolium perenne L., as representatives of di- and mono-cotyledonous weeds, respectively. Narciclasine was identified as the bioactive compound in Narcissus. The extract of Amaryllis belladonna L. was equally active, but did not contain any narciclasine. Bioassay-guided fractionation of the A. belladonna extract resulted in the identification of lycorine as the bio-active compound. The IC₅₀ measured for radicle growth inhibition was 0.10 µM for narciclasine and 0.93 µM for lycorine, compared to 0.11 mM of chlorpropham, a synthetic herbicide. Therefore, the leftover biomass from the spring bulb industry represents an interesting potential source for promising allelochemicals for further studies on weed growth inhibition.
authors.affiliation: Natural Product Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden, The Netherlands. dinarsarid@chem.leidenuniv.nl
authors.forename: Dinar S C
authors.initials: DS
authors.lastname: Wahyuni
authors.forename: Frank
authors.initials: F
authors.lastname: van der Kooy
authors.forename: Peter G L
authors.initials: PG
authors.lastname: Klinkhamer
authors.forename: Rob
authors.initials: R
authors.lastname: Verpoorte
authors.forename: Kirsten
authors.initials: K
authors.lastname: Leiss
mesh_terms: D047151:Amaryllidaceae Alkaloids / Q000494:pharmacology; D018533:Biomass; D005591:Chemical Fractionation / Q000379:methods*; D002748:Chlorpropham / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry*; D006540:Herbicides / Q000138:chemical synthesis* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D008129:Lolium / Q000187:drug effects; D010617:Phenanthridines / Q000494:pharmacology; D010675:Pheromones / Q000138:chemical synthesis* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry*; D057685:Plant Weeds / Q000187:drug effects; D058728:Weed Control / Q000379:methods
chemical_list: D047151:Amaryllidaceae Alkaloids; D006540:Herbicides; D010617:Phenanthridines; D010675:Pheromones; D002748:Chlorpropham; C010753:narciclasine; C015330:lycorine