Plant metabolism of chlorinated anilines: Isolation and identification of N-glucosyl and N-malonyl conjugates

Winkler, R.; Sandermann, Heinrich

doi:10.1016/0048-3575(89)90122-3

Cited by 38 publications

(33 citation statements)

References 19 publications

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“…Recovery of metabolites from plant cell culture medium also has been reported in the case of the N ‐malonyl conjugate of 3,4‐dichloroaniline. However, in that case, the glucoside conjugate of this chemical was only associated with the cells [20–22]. Another ester glycoside, 2,4‐dichlorophenyl‐β‐D‐(6‐O‐acetyl)‐glucopyranoside (DCP‐Glc‐acetyl), was characterized by ESI‐MS (Table 1) from peak 9 but was found only in small amounts.…”

Section: Resultsmentioning

confidence: 99%

Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Laurent¹,

Canlet²,

Debrauwer³

et al. 2007

Enviro Toxic and Chemistry

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In plant tissues, xenobiotics often are conjugated with natural constituents such as sugars, amino acids, glutathione, and malonic acid. Usually, conjugation processes result in a decrease in the reactivity and toxicity of xenobiotics by increasing the water solubility and polarity of conjugates, and reducing their mobility. Due to their lack of an efficient excretory system, xenobiotic conjugates finally are sequestered in plant storage compartments or cell vacuoles, or are integrated as bound residues in cell walls. Chlorophenols are potentially harmful pollutants that are found in numerous natural and agricultural systems. We studied the metabolic fate of 2,4-dichlorophenol (DCP) in cell-suspension cultures of tobacco (Nicotiana tabacum L.). After a standard metabolism experiment, 48 h of incubation with a [U-phenyl-(14)C]-DCP solution, aqueous extracts of cell suspension cultures were analyzed by high-performance liquid chromatography (HPLC). Metabolites then were isolated and their chemical structures determined by enzymatic and chemical hydrolyses, electrospray ionization-mass spectrometry in negative mode (ESI-NI), and (1)H nuclear magnetic resonance analyses. The main terminal metabolites identified were DCP-glycoside conjugates, DCP-(6-O-malonyl)-glucoside, DCP-(6-O-acetyl)-glucoside, and their precursor, DCP-glucoside. More unusual and complex DCP conjugates such as an alpha(1-->6)-glucosyl-pentose and a triglycoside containing a glucuronic acid were further characterized. All the metabolites identified were complex glycoside conjugates. However, these conjugates still may be a source of DCP in hydrolysis reactions caused by microorganisms in the environment or in the digestive tract of animals and humans. Removal of xenobiotics by glycoside conjugation thus may result in underestimation of the risk associated with toxic compounds like DCP in the environment or in the food chain.

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Section: Resultsmentioning

confidence: 99%

Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Laurent¹,

Canlet²,

Debrauwer³

et al. 2007

Enviro Toxic and Chemistry

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“…As a control, [ 14 C]‐DCA was incubated in sterile growth medium for 24 h, with the majority of the radiolabel recovered as unchanged parent compound at all four time points. In addition, [ 14 C]‐DCA‐glc was formed in the growth medium by chemical conjugation with available glucose (Winkler and Sandermann, 1989), such that by 24 h, 8.8% of the administered DCA was glucosylated in the absence of root tissue. This degree of chemical‐conjugation was greater than determined previously (Lao et al.…”

Section: Resultsmentioning

confidence: 99%

Functional importance of the family 1 glucosyltransferase UGT72B1 in the metabolism of xenobiotics in Arabidopsis thaliana

Brazier-Hicks

Edwards²

2005

The Plant Journal

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SummaryThe Arabidopsis type 1 UDP-glucose-dependent glucosyltransferase UGT72B1 is highly active in conjugating the persistent pollutants 3,4-dichloroaniline (DCA) and 2,4,5-trichlorophenol (TCP). To determine its importance in detoxifying xenobiotics in planta, mutant plants where the respective gene has been disrupted by T-DNA insertion have been characterized. Extracts from the knockout ugt72B1 plants showed radically reduced conjugating activity towards DCA and TCP and the absence of immunodetectable UGT72B1 protein. In contrast, activities towards phenolic natural products were unaffected. When aseptic root cultures were fed [ 14 C]-DCA, compared with wild types, the ugt72B1 plants showed a reduced rate of uptake of the xenobiotic and very little metabolism to soluble DCA-glucose or associated polar conjugates. Instead, the knockouts accumulated non-extractable radioactive residues, most probably associated with lignification. When the feeding studies were carried out with [14 C]-TCP, rates and routes of metabolism were identical in the wild type and knockouts, with TCP-glucoside a major product in both cases. Similar differential effects on the metabolism of DCA and TCP were obtained in whole plant studies with wild type and ugt72B1 mutants, demonstrating that while UGT72B1 had a central role in metabolizing chloroanilines in Arabidopsis, additional UGTs could compensate for the conjugation of TCP in the knockout. TCP was equally toxic to wild type and ugt72B1 plants, while surprisingly, the knockouts were less sensitive to DCA. From this it was concluded that the glucosylation of DCA may not be as effective in xenobiotic detoxification as bound-residue formation.

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“…Chlorinated anilines are released into the environment in the biotic and abiotic degradation of acylanilide, phenylurea and carbamate pesticides (Winkler and Sandermann 1989, Lao et al 2003, Giacomazzi and Cochet 2004. In the higher plants chlorinated anilines are metabolised to polar compounds and accumulate in vacuoles (Brazier-Hicks and Edwards 2005) or are incorporated into the cell wall macromolecules (Sandermann 2004).…”

Section: Incorporation Of Chlorinated Anilines Into Ligninmentioning

confidence: 99%

The effect of lignin content and lignin modification on Norway spruce wood properties and decay resistance

Raiskila¹

2008

Diss. For.

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This thesis describes studies with three different Norway spruce cutting clones in three growing environments differing in soil and climatic conditions within the boreal zone. The main aim was to follow variation in the radial growth rate, wood properties and lignin content and to modify wood lignin with a natural monolignol, coniferyl alcohol, by making use of inherent wood peroxidases. In addition, the incorporation of chlorinated anilines into lignin was studied with synthetic model compounds and synthetic lignin preparations to show whether unnatural compounds originating from pesticides could be bound in the lignin polymer. Annual ring width, latewood proportion and wood properties such as weight density, modulus of rupture (MOR) and modulus of elasticity (MOE) were determined. Fourier transform infrared (FTIR) spectroscopy was applied to the quantitative estimation of lignin in heartwood, sapwood and earlywood samples by using a principal component regression (PCR) technique. Wood blocks were treated with coniferyl alcohol by using a vacuum impregnation method. The effect of impregnation was assessed by FTIR and by a fungal decay test. Trees from a fertile site showed the highest growth rate and sapwood lignin content and the lowest latewood proportion, weight density and MOR. Trees from a medium fertile site had the lowest growth rate and the highest latewood proportion, weight density, MOE and MOR. The most rapidly growing clone showed the lowest latewood proportion, weight density, MOE and MOR. The slowest growing clone had the lowest sapwood lignin content and the highest latewood proportion, weight density, MOE and MOR. Fairly large variation was found between the individual trees and between the growing seasons but much less variation between the sites and between the clones. The coniferyl alcohol impregnation increased the content of different lignin-type phenolic compounds in the wood as well as wood decay resistance against a white-rot fungus, Coriolus versicolor. Also the incorporation of chlorinated anilines into lignin was shown to be possible and the intermediate quinone methide was seen to be trapped by 3,4-dichloroaniline during the dehydrogenative polymerization of coniferyl alcohol, which resulted in a dimer of coniferyl alcohol with a β-O-4 structure and with dichloroaniline bound by a benzylamine bond. In conclusion, in this thesis it was shown that the different Norway spruce cutting clones maintained clone-dependent wood properties in the different growing sites although variation between tree individuals was high and climatic factors affected growth. It was also shown that the natural monolignol, coniferyl alcohol, and chlorinated anilines could be incorporated into the lignin polymer in vivo and in vitro, respectively. The coniferyl alcohol impregnation experiment resulted in the improved resistance of the wood blocks to fungal decay, while chlorinated anilines were covalently bound into the lignin polymer and they could not be released by mild acid hydrolysis.

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Plant metabolism of chlorinated anilines: Isolation and identification of N-glucosyl and N-malonyl conjugates

Cited by 38 publications

References 19 publications

Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Functional importance of the family 1 glucosyltransferase UGT72B1 in the metabolism of xenobiotics in Arabidopsis thaliana

The effect of lignin content and lignin modification on Norway spruce wood properties and decay resistance

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Plant metabolism of chlorinated anilines: Isolation and identification of N-glucosyl and N-malonyl conjugates

Cited by 38 publications

References 19 publications

Metabolic fate of [14C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Metabolic fate of [14C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Functional importance of the family 1 glucosyltransferase UGT72B1 in the metabolism of xenobiotics in Arabidopsis thaliana

The effect of lignin content and lignin modification on Norway spruce wood properties and decay resistance

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Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures

Metabolic fate of [¹⁴C]‐2,4‐dichlorophenol in tobacco cell suspension cultures