title: Herbicidal activity of glucosinolate degradation products in fermented meadowfoam ( Limnanthes alba ) seed meal.
abstract: Meadowfoam ( Limnanthes alba ) is an oilseed crop grown in western Oregon. After extraction of the oil from the seeds, the remaining seed meal contains 2-4% of the glucosinolate glucolimnanthin. This study investigated the effect of fermentation of seed meal on its chemical composition and the effect of the altered composition on downy brome ( Bromus tectorum ) coleoptile emergence. Incubation of enzyme-inactive seed meal with enzyme-active seeds (1% by weight) resulted in complete degradation of glucolimnanthin and formation of 3-methoxybenzyl isothiocyanate in 28% yield. Fermentation in the presence of an aqueous solution of FeSO(4) (10 mM) resulted in the formation of 3-methoxyphenylacetonitrile and 2-(3-methoxyphenyl)ethanethioamide, a novel natural product. The formation of the isothiocyanate, the nitrile, and the thioamide, as a total, correlated with an increase of herbicidal potency of the seed meal (r(2) = 0.96). The results of this study open new possibilities for the refinement of glucosinolate-containing seed meals for use as bioherbicides.
authors.affiliation: Departments of Pharmaceutical Sciences and Statistics and the Columbia Basin Agricultural Research Center, Oregon State University, Corvallis, Oregon 97331, USA. fred.stevens@oregonstate.edu
authors.forename: Jan F
authors.initials: JF
authors.lastname: Stevens
authors.forename: Ralph L
authors.initials: RL
authors.lastname: Reed
authors.forename: Susan
authors.initials: S
authors.lastname: Alber
authors.forename: Larry
authors.initials: L
authors.lastname: Pritchett
authors.forename: Stephen
authors.initials: S
authors.lastname: Machado
mesh_terms: D031724:Bromus / Q000187:drug effects; D005285:Fermentation; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D019684:Magnoliopsida / Q000737:chemistry / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D013861:Thiocyanates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D013863:Thioglucosides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D006540:Herbicides; D013861:Thiocyanates; D013863:Thioglucosides; C055576:glucolimnanthin