Plant metabolite, herbicide

Sulfentrazone is a broad-spectrum, pre-emergent herbicide that provides good control over broadleaf weeds, grasses and sedges in crops and turf. The metabolism of sulfentrazone in animals and plants is similar. The major plant metabolite of sulfentrazone is 3-hydroxymethyl sulfentrazone (HMS). The soybean tolerance of 0.05 mg kg includes residues of sulfentrazone plus its major metabolite, HMS. The rotational crop tolerance includes residues of sulfentrazone and its major metabolites, HMS and... 

The metabolism of s-triazines has been the subject of extensive research since the 1950s to the present time. Much of this research has been the subject of review articles published over the years since s-triazines were introduced. The metabolism of -triazine herbicides in animals and plants and their degradation in soil were the subject of a review by Knuesli et al. (1969), later updated and revised by Esser et al. (1975) as a second edition. The metabolism of. v-triazines in plants was also reviewed by Shimabukuro et al. (1971a). Naylor (1976) published a review of herbicide metabolism in plants that included the. v-triazines. Lamoureux et al. (1998) reported on the identification of several plant metabolites of atrazine and simazine. 

The environmental implication of the results with atrazine is that application of herbicides, which are widely used in corn agriculture, can lead to mutagenic plant metabolites in crops. More generally, this result suggested that, like mammalian metabolism of promutagens,... 

The difference between pyrazoxyfen and pyrazolynate is only the chosen prodrug system. In plants, both herbicides were metabolized to 4-(2,4-dichlorobenzoyl)-l,3-dimethyl-5-hydroxypyrazole (8). Pyrazolynate is only slightly soluble in water, but, once dissolved, is rapidly hydrolyzed to the herbicidally active metabolite [11]. In contrast, pyrazoxyfen shows considerable stability in aqueous solutions [16]. 

Several of the top 20 pharmaceuticals in gross sales in 1992 were natural products or close derivatives thereof (eg. Mevacor, Ceclor). Of the top 20 crop chemicals in this same period, only one class of compounds, the pyrethroids, are based on a natural substance, the plant metabolite pyrethrin. Three active areas of chemistry have the potential to impact this situation within the next ten years the methoxyacrylate family of fungicides based upon the fungal metabolite, strobilurin Basta, a post-emergent broad-spectrum herbicide based upon the Streptomyces viridochromogenes metabolite phosphinothricylalanylalanine and avermectin, and its semi-synthetic derivatives, insecticides originating from Streptomyces avermitilis. 

The current methodology to determine residues of alachlor, acetochlor, propachlor, and butachlor in crops and animal products was developed over the last two decades by researchers at the Monsanto Company. These herbicides degrade rapidly in plants and animals to numerous metabolites that can be hydrolyzed to common aniline moieties. Little to no parent herbicide is found as intact residue in crops and animal products therefore, the residue methodology focuses on the determination of the common moieties that are derived from the parent herbicides and their metabolites. Initially, gas chromatography (GC) with flame ionization detection, nitrogen-phosphorus... 

Dinitroaniline herbicides show minimal plant systematic translocation properties with the majority of the absorbed residues in the root tissues. Metabolites identified include traces of Al-dealkylation, alkyl and aryl hydroxylation and nitro reduction products. Low levels of dinitroaniline herbicide residues have been reported in raw agricultural commodities according to Good Agricultural Practice. 

Extraction and cleanup of diphenyl ether herbicide metabolites in plants... 

One application using MAE is a method to determine imidazolinone herbicides and their respective metabolites in plant tissue." Current residue methodologies for determining imazethapyr (imidazolinone herbicide) and its metabolites in crops involve laborious, time-consuming cleanup procedures after an aqueous/organic extraction. 

LANGE, B.M., KETCHUM, R.E.B., CROTEAU, R., Isoprenoid biosynthesis metabolite profiling of peppermint oil gland secretory cells and application to herbicide target analysis, Plant Physiol., 2001,127, 305-314. 

The presence of free anilines or other metabolites in soils and plants has been reported [123, 139-143]. Some work has suggested that they are very strongly bound to soil components and the findings of Caverly and Denney [138] are in agreement with these conclusions. The presence in soils of metabolites of Linuron that possess the urea structure have been reported [123, 142] these are produced mainly by microbiological degradation. The dimethyl derivative is considered to be inactive whereas the monomethyl metabolite has phytotoxicity approaching that of the parent herbicide [142], It is probable that the procedure reported by... 

Plant. Trifluralin was absorbed by carrot roots in greenhouse soils pretreated with the herbicide (0.75 Ib/acre). The major metabolite formed was a,a,a-trifluoro-2,6-dinitro-7V-(/i-propyl-toluene)-p-toluidine (Golab et al., 1967). Two metabolites of trifluralin that were reported in goosegrass Eleucine indica) were 3-methoxy-2,6-dinitro-A7A-dipropyl-4-(trifluoromethyl)benz-enamine and A-(2,6-dinitro-4-(trifluoromethyl)phenyl)-jV-propylpropanamide (Duke et al., 1991). 

The triketones (Fig. 20), the most recent class of herbicides, were discovered in 1986 and introduced commercially (e.g. sulcotrione) in 1991. While several papers report that the triketones herbicides were derived from the plant secondary metabolite leptospermone (Fig. 20) that was isolated from the bottlebrush plant [Callistemon spp.) [Ref. 101], there is a report that suggests that the discovery may have been more serendipitous. ... 

Plant residues can provide substrates for the production of phytotoxic metabolites by soil microorganisms but they can also support the growth of pathogens and other deleterious micro-organisms. This is illustrated by reference to the problems of establishing crops drilled in the presence of straw residues and of decaying weed and grass residues that have been previously killed with herbicides. 

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