Degradation of niclosamide (2',5-dichloro-4'-nitrosalicylanilide) in sediment and water systems

Muir, D.; Yarechewski, Alvin L.

doi:10.1021/jf00114a005

Cited by 26 publications

(24 citation statements)

References 3 publications

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“…Table 3 shows the values of biodegradability and biological activity of the prepared surfactant. The results indicate that these compounds have low biodegradability [9] and high biological activity.…”

Section: Thermodynamic Parametersmentioning

confidence: 95%

Surface Properties and Biological Activity of Select Cationic Surfactants

Mahmoud

Ismail

Ghazy

2007

J Surfact & Detergents

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Section: Thermodynamic Parametersmentioning

confidence: 95%

Surface Properties and Biological Activity of Select Cationic Surfactants

Mahmoud

Ismail

Ghazy

2007

J Surfact & Detergents

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“…Aminoniclosamide was first reported as a byproduct of niclosamide degradation in aquatic systems by Muir and Yarechewski (12) and confirmed by Graebing et al (13). Previously, aminoniclosamide was shown to be formed only in rat studies (12). Hydroxyniclosamide and 5-chlorosalicylic acid ranged from 1 to 5%.…”

Section: Light Transmittance In Relation To Soil Depthmentioning

confidence: 97%

“…Hydroxyniclosamide and 5-chlorosalicylic acid ranged from 1 to 5%. The formation of 5-chlorosalicylic acid has only been inferred in previous studies involving environmental systems by the observation of the corresponding degradate 2-chloro-4-nitroaniline (12), although it has been observed in direct photolysis on glass slides (14). Hydroxyniclosamide has not been previously identified in fate and metabolism studies.…”

Section: Light Transmittance In Relation To Soil Depthmentioning

confidence: 99%

Effect of Soil Moisture and Sample Depth on Pesticide Photolysis

Frank¹,

Graebing²,

Chib³

2002

J. Agric. Food Chem.

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The effects of soil depth and moisture on pesticide photolysis were studied. Moist soil at depths of 3, 2.5, 2, 1.5, 1, and 0.5 mm were each dosed at 2.5 microg/g with (14)C-niclosamide and photolyzed under a xenon lamp at constant temperature. Samples were removed after 20, 40, 110, and 153 h of continuous irradiation. The decrease in percent of niclosamide and the appearance of degradates were followed by analyzing the soil extracts by HPLC. A corresponding set of experiments used air-dried soil. An experiment was also performed using initially moist soil which was permitted to dry during photolysis but returned to moist conditions at each sampling. Qualitative and quantitative differences were found in the rate and route of degradation of niclosamide under these conditions. These differences have resulted from a combination of reduced photochemical activity and microbial population in dry soil. The half-lives of niclosamide in the dry soils were 2 to 5 times longer than those in the moisture-maintained soil. There was also a noticeable difference in the half-lives in soil of different depths. Moisture-maintained soil showed a uniform linear increase in half-life from 95 to 195 h as soil depth increased from 0.5 mm to 3.0 mm. With air-dried soil the half-lives were greatly dependent on soil depth, showing a much broader range of 199 h at 0.5-mm to 1064 h in 3.0-mm soil. An experimental design is described which maintains soil temperature and moisture to preset conditions.

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“…The redox potentials of the samples were measured immediately using an Orion Research, Inc. (Beverly, MA), model 96-78-00 redox electrode and a Fisher (Pittsburgh, PA) model 805 MP pH meter. Redox potential readings of <350 mV were observed in every sample that was taken, indicating that anaerobic conditions were maintained in the test systems (13). Samples were then centrifuged at 2000 rpm for ∼4-10 min.…”

Section: High-performance Liquid Chromatography (Hplc)mentioning

confidence: 99%

“…Photolysis causes 51% degradation of the parent compound after 7 days of exposure in pH 6.9 buffer (12). Degradation in river and pond sediment/water systems yielded half-lives of 1.1-3.9 days (13). The purpose of this study was to determine the rates of degradation and half-lives of niclosamide in sediment/water environments and to identify and quantify niclosamide and its metabolites, thereby expanding on the previous studies.…”

Section: Introductionmentioning

confidence: 99%

Metabolism of Niclosamide in Sediment and Water Systems

Graebing¹,

Chib²,

Hubert³

et al. 2004

J. Agric. Food Chem.

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A series of experiments analyzed the kinetics and mechanisms of [(14)C]niclosamide degradation. The aerobic aquatic metabolism of [(14)C]niclosamide was studied in nonsterile river water/sediment mixtures. Test systems, maintained under aerobic conditions, were treated with niclosamide and incubated in the dark at 25.0 +/- 1.0 degrees C for 30 days. Half-lives of 4.9 and 5.4 days were calculated for the chlorosalicylic acid- and chloronitroaniline-labeled test systems, respectively. From 0 to 21 days after treatment (DAT), the only metabolism product observed in either test system was aminoniclosamide. At the final sampling interval, five peaks were resolved from the chlorosalicylic acid label, and three peaks were resolved from the chloronitroaniline label test substance. By 30 DAT, sediment-bound residues represented approximately 70% of the observed radioactivity. For the anaerobic aquatic metabolism of [(14)C]niclosamide, test systems were incubated under anaerobic conditions for 365 days. Half-lives of 0.65 day for the chlorosalicylic acid label and 2.79 days for the chloronitroaniline label were calculated. From 0 to 3 DAT, niclosamide was first transformed into aminoniclosamide. Aminoniclosamide is readily formed, as it was observed in the chlorosalicylic acid label 0 DAT sampling. Several minor metabolites were observed in the water and sediment extracts. None of these metabolites were formed to a significant amount until the parent niclosamide dissipated below the detection limit. Two of the byproducts from these metabolism studies are polar unknowns eluting at 3 and 5 min by HPLC, similar to the unknowns observed in aqueous photolysis studies.

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Degradation of niclosamide (2',5-dichloro-4'-nitrosalicylanilide) in sediment and water systems

Cited by 26 publications

References 3 publications

Surface Properties and Biological Activity of Select Cationic Surfactants

Surface Properties and Biological Activity of Select Cationic Surfactants

Effect of Soil Moisture and Sample Depth on Pesticide Photolysis

Metabolism of Niclosamide in Sediment and Water Systems

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