Studies on the nature and identity of bound chloroaniline residues in plants

Still, Gerald G.; Balba, H. M.; Mansager, Eugene R.

doi:10.1021/jf00106a014

Cited by 36 publications

(33 citation statements)

References 7 publications

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“…These pesticide degradation products have been shown to be associated with lignin from roots of rice exposed to the compounds during growth. 30 Similar to the observations made for 1, aniline derivatives were also incorporated into artificial lignin polymers produced by peroxidase-mediated polymerization of coniferyl alcohol. A covalent binding mechanism has been proposed involving the nucleophilic addition of the amino group to quinone methides, which occur as intermediates during lignin formation, thus binding to the benzylic position of the coniferyl alcohol units.…”

Section: ■ Results and Discussionsupporting

confidence: 60%

Matrix-Bound 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone in Tobacco: Quantification and Evidence for an Origin from Lignin-Incorporated Alkaloids

Lang

Vuarnoz

2014

J. Nat. Prod.

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Substantial quantities of the carcinogenic tobacco-specific N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (1; NNK) are still found in the mainstream smoke of tobacco exhaustively extracted with water, indicating the presence of an insoluble, matrix-bound form. Soluble and matrix-bound concentrations of 1 in tobacco were determined by applying a new method using sequential aqueous extraction at room temperature and at 130 °C. On average, 77% and 53% of the total content of 1 were matrix-bound in air-cured (Burley type) and flue-cured tobaccos, respectively. Thermal release of 1 from its matrix-bound form above ca. 200 °C can account for a large fraction of its concentration in cigarette mainstream smoke. An already matrix-bound alkaloid precursor of matrix-bound 1 was identified in vascular tissue of green leaf midribs. The incubation of vascular cell-wall preparations with the lignin precursor coniferyl alcohol and isotopically labeled nicotine or pseudooxynicotine (2) led to the formation of labeled matrix-bound 1 after nitrosation, suggesting that incorporation of nicotine or its oxidized product 2 during lignin polymerization is the origin of the formation of matrix-bound 1.

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Section: ■ Results and Discussionsupporting

confidence: 60%

Matrix-Bound 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone in Tobacco: Quantification and Evidence for an Origin from Lignin-Incorporated Alkaloids

Lang

Vuarnoz

2014

J. Nat. Prod.

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“…This study accords with our earlier observations that showed difficult extraction of 3-CA from potato peel [25]. In reviewing the literature, several investigations have been reported on the fate of chloroaniline compounds in the plants indicating bound or nonextractable residues of these compounds [26][27][28].…”

Section: Introductionsupporting

confidence: 92%

Adsorption of 3-Chloroaniline on Potato Skin in Aqueous Solution

Mohammed

Flowers

Duncan

2016

Indian Journal of Materials Science

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The adsorption behaviour of aromatic amine 3-chloroaniline (3-CA) from aqueous solution on fresh potato skin was investigated. A series of batch experiments were conducted under different experimental conditions of contact time, 3-chloroaniline concentration, weight of potato skin, pH, temperature, and ionic strength using RP-HPLC analysis. Adsorption equilibrium of 3-chloroaniline at concentration of 10 g/mL on 1 g weight of chopped potato skin was achieved in 24 hours. Using different varieties of potato skin showed that the adsorption of 3-CA on Nicola variety is higher compared to Sante and Maris Peer varieties. Adsorption on potato skin was found to be generally higher compared to cortex and pith tissues. Analysis of adsorption isotherm shows that equilibrium data was fitted to Freundlich model ( 2 = 0.977). Maximum adsorption capacities of 3-chloroaniline were found in the pH range from 3 to 9, whereas low adsorption quantities were found in high acidic and high basic solutions (pH 2 and pH 13, resp.). Adsorption capacity increased with an increase in temperature from 4 ∘ C to 30 ∘ C but decreased with further increase of temperature to 40 ∘ C. Testing the ionic strength showed that increasing the concentration of electrolyte reduces the adsorption efficiency. This study indicated that the fresh potato skin (without any treatment) is possible to use as a new adsorbent for removal of 3-chloroaniline from industrial waste water.

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“…By 1981, 1 H and 13 C NMR spectroscopy had identified the benzylamine structure of Fig 1A in lignin conjugates of chloroanilines 28, 29. This structural assignment has recently been confirmed using more sophisticated NMR techniques 52.…”

Section: Chemical Linkage Typesmentioning

confidence: 91%

“…In addition, the cutin component of leaf surfaces has been shown to act as a covalent binding partner,27 with photochemistry being involved in the cases of chlorothalonil22, 23 and parathion 25. Defined adducts have been chemically or enzymatically prepared in the case of xenobiotic lignin28, 29 and protein30, 31 conjugates. Plants are also known to be capable of mutagenic activation, so that binding of xenobiotics to DNA and soluble proteins appears possible 32, 33.…”

Section: Plant Matrix Macromolecules Involvedmentioning

confidence: 99%

Bound and unextractable pesticidal plant residues: chemical characterization and consumer exposure

Sandermann

2004

Pest Management Science

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Plants are well known to incorporate pesticides into bound and unextractable residues that resist solubilization in common laboratory solvents and are therefore not accessible to standard residue analysis. A characterization of such residues has been proposed for incorporation rates above trigger values of 0.05 mg kg(-1) parent pesticide equivalents, or percentage values of 10% (United States Environmental Protection Agency, 1995) or 25% (Commission of the European Communities, 1997) of the total radioactive residue. These trigger values are often exceeded. The present review describes the current status of the chemical characterization and animal bioavailability of bound and unextractable residues that may be xenobiotic in nature or result from natural recycling of simple degradation products. The latter case represents a mechanism of detoxification. Bound residues have been shown to be covalent or non-covalent in nature. With regard to the plant matrix molecules involved, incorporation into proteins, lignins, pectins, hemicelluloses and cutins has been demonstrated, and four covalent linkage types are known. Animal feeding experiments have revealed cases of low as well as high bioavailability. Many of the studies are limited by experimental uncertainties and by results only being reported as relative percentage values rather than absolute exposure. A preliminary value of absolute exposure from bound and unextractable residues is derived here for the first time from eight case studies. The mean exposure (ca 1.5 mg kg(-1) pesticidal equivalents) exceeds some of the existing maximum residue levels (MRLs) of residual free pesticides that are typically in the range of 0.05-1 mg kg(-1). A mathematical framework for the correction of current maximum residue levels is presented for cases of highly bioavailable bound residues. As bound pesticidal residues in food plants could represent a source of significant consumer exposure, an experimental test scheme is proposed here. It consists of basic chemical characterization, model digestibility tests and, in exceptional cases, animal bioavailability and additional toxicological studies.

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Studies on the nature and identity of bound chloroaniline residues in plants

Cited by 36 publications

References 7 publications

Matrix-Bound 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone in Tobacco: Quantification and Evidence for an Origin from Lignin-Incorporated Alkaloids

Matrix-Bound 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone in Tobacco: Quantification and Evidence for an Origin from Lignin-Incorporated Alkaloids

Adsorption of 3-Chloroaniline on Potato Skin in Aqueous Solution

Bound and unextractable pesticidal plant residues: chemical characterization and consumer exposure

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