title: Synthesis and evaluation as biodegradable herbicides of halogenated analogs of L-meta-tyrosine.
abstract: L-meta-tyrosine is an herbicidal nonprotein amino acid isolated some years ago from fine fescue grasses and characterized by its almost immediate microbial degradation in soil (half-life <24 h). Nine monohalogenated or dihalogenated analogs of this allelochemical have been obtained through a seven-step stereoselective synthesis from commercial halogenated phenols. Bioassays showed a large range of biological responses, from a growth root inhibition of lettuce seedling similar to that noted with m-tyrosine [2-amino-3-(2-chloro-5-hydroxyphenyl)propanoic acid or compound 8b] to an increase of the primary root growth concomitant with a delay of secondary root initiation [2-amino-3-[2-fluoro-5-hydroxy-3-(trifluoromethyl)phenyl]propanoic acid or compound 8h]. Compound 8b was slightly less degraded than m-tyrosine in the nonsterilized nutritive solution used for lettuce development, while the concentration of compound 8h remained unchanged for at least 2 weeks. These data indicate that it is possible to manipulate both biological properties and degradation of m-tyrosine by halogen addition.
authors.affiliation: Institut de Chimie des Milieux et des Matériaux de Poitiers, Unité Mixte de Recherche CNRS 7285, Université de Poitiers, 40 Avenue du Recteur Pineau, 86022, Poitiers Cedex, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Movellan
authors.forename: Françoise
authors.initials: F
authors.lastname: Rocher
authors.forename: Zohra
authors.initials: Z
authors.lastname: Chikh
authors.forename: Cécile
authors.initials: C
authors.lastname: Marivingt-Mounir
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bonnemain
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Chollet
mesh_terms: D001673:Biodegradation, Environmental; D031751:Festuca / Q000378:metabolism; D006207:Half-Life; D054879:Halogenation; D006540:Herbicides / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D018545:Lactuca / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D012987:Soil; D012988:Soil Microbiology; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
chemical_list: D006540:Herbicides; D012987:Soil; D014443:Tyrosine