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At least 19 recordsLinked to original sources
PubMed2005

Development of a pressurized liquid extraction and clean-up procedure for the determination of alpha-endosulfan, beta-endosulfan and endosulfan sulfate in aged contaminated Ethiopian soils.

Pressurized liquid extraction (PLE) was investigated for the extraction of two endosulfan isomers and their metabolite from two real contaminated soil samples. PLE for 3x10min at 100 degrees C was proven to be more exhaustive than Soxhlet extraction (SOX) in one soil sample. On the other soil sample investigated the method was found to be equally exhaustive as SOX. The use of hazardous organic solvents such as n-hexane, toluene, and diethyl ether has been avoided in PLE and clean-up. Instead less toxic solvents have been used both at the extraction step (acetone/n-heptane) and clean-up step (ethyl acetate/n-heptane). A column Florisil clean-up procedure that consumes relatively low solvent volumes has been optimized and applied to purify soil extracts. The developed analytical procedure was validated by applying it to a certified reference soil material (CRM811-050). A recovery of 103% total endosulfan residue was obtained versus certified values.

Chemical Fractionation↗
PubMed2004

Algal degradation of a known endocrine disrupting insecticide, alpha-endosulfan, and its metabolite, endosulfan sulfate, in liquid medium and soil.

The role of algae in the persistence, transformation, and bioremediation of two endocrine disrupting chemicals, alpha-endosulfan (a cyclodiene insecticide) and its oxidation product endosulfan sulfate, in soil (incubated under light or in darkness) and a liquid medium was examined. Incubation of soil under light dramatically decreased the persistence of alpha-endosulfan and enhanced its transformation to endosulfan sulfate, over that of dark-incubated soil samples, under both nonflooded and flooded conditions. This enhanced degradation of soil-applied alpha-endosulfan was associated with profuse growth of indigenous phototrophic organisms such as algae in soil incubated under light. Inoculation of soil with green algae, Chlorococcum sp. or Scenedesmus sp., further enhanced the degradation of alpha-endosulfan. The role of algae in alpha-endosulfan degradation was convincingly demonstrated when these algae degraded alpha-endosulfan to endosulfan sulfate, the major metabolite, and endosulfan ether, a minor metabolite, in a defined liquid medium. When a high density of the algal inoculum was used, both metabolites appeared to undergo further degradation as evident from their accumulation only in small amounts and the appearance of an endosulfan-derived aldehyde. Interestingly, beta-endosulfan was detected during degradation of alpha-endosulfan by high density algal cultures. These algae were also capable of degrading endosulfan sulfate but to a lesser extent than alpha-endosulfan. Evidence suggested that both alpha-endosulfan and endosulfan sulfate were immediately sorbed by the algae from the medium, which then effected their degradation. Biosorption, coupled with their biotransformation ability, especially at a high inoculum density, makes algae effective candidates for remediation of alpha-endosulfan-polluted environments.

Chlorophyta↗
PubMed2005

Biodegradation of the organochlorine insecticide, endosulfan, and the toxic metabolite, endosulfan sulfate, by Klebsiella oxytoca KE-8.

Biodegradation of endosulfan, a chlorinated cyclodiene insecticide, is generally accompanied by production of the more toxic and more persistent metabolite, endosulfan sulfate. Since our reported endosulfan degrader, Klebsiella pneumoniae KE-1, failed to degrade endosulfan sulfate, we tried to isolate an endosulfan sulfate degrader from endosulfan-polluted soils. Through repetitive enrichment and successive subculture using mineral salt medium containing endosulfan or endosulfan sulfate as the sole source of carbon and energy, we isolated a bacterium capable of degrading endosulfan sulfate as well as endosulfan. The bacterium KE-8 was identified as Klebsiella oxytoca from the results of 16S rDNA sequence analysis. In biodegradation assays with KE-8 using mineral salt medium containing endosulfan (150 mg l(-1)) or endosulfan sulfate (173 mg l(-1)), the biomass was rapidly increased to an optical density at 550 nm of 1.9 in 4 days and the degradation constants for alpha- and beta-endosulfan, and endosulfan sulfate were 0.3084, 0.2983 and 0.2465 day(-1), respectively. Analysis of the metabolites further suggested that K. oxytoca KE-8 has high potential as a biocatalyst for bioremediation of endosulfan and/or endosulfan sulfate.

Biodegradation, Environmental↗
PubMed2006

Development of an in vitro blood-brain barrier model to study the effects of endosulfan on the permeability of tight junctions and a comparative study of the cytotoxic effects of endosulfan on rat and human glial and neuronal cell cultures.

Endosulfan, an organochlorine (OC) insecticide that belongs to the cyclodiene group, is one of the most commonly used pesticides to control pests in vegetables, cotton, and fruits. Porcine brain microvascular endothelial cells were used to develop a model to study the effects of endosulfan on the permeability of tight junctions in the blood-brain barrier (BBB). BBB permeability, measured as transendothelial electrical resistance, decreased in a dose- and time-dependent manner when treated with alpha-endosulfan, beta-endosulfan, or endosulfan sulfate. Cytotoxicity testing revealed that the three endosulfans did not cause cell death at concentrations of 10 microM and below. The ratio of the average permeability of the filter-grown endothelial cell monolayer to 14C-endosulfan (Pe) going from the outer to the inner compartments with that going from the inner to the outer compartments was approximately 1:1.2-2.1 after exposure to concentrations of 0.01-10 microM. alpha-Endosulfan, beta-endosulfan, and endosulfan sulfate had cytotoxic effects on rat glial (C6) and neuronal (PC12) cell cultures as well as on human glial (CCF-STTG1) and neuronal (NT2) cell cultures. The effects of alpha-endosulfan were highly selective, with a wide range of LC50 values found in the different cultures, ranging from 11.2 microM for CCF-STTG1 cells to 48.0 microM for PC12 cells. In contrast, selective neurotoxicity was not so manifest in glial and neuronal cell cultures after exposure to endosulfan sulfate, as LC50 values were in the range of 10.4-21.6 microM. CCF-STTG1 cells were more sensitive to alpha-endosulfan and endosulfan sulfate, whereas NT2 cells were more sensitive to beta-endosulfan.

Animals↗
PubMed2003

Stereoselective degradation of aqueous endosulfan in modular estuarine mesocosms: formation of endosulfan gamma-hydroxycarboxylate.

Solutions of alpha-endosulfan, beta-endosulfan, and technical grade endosulfan (70alpha:30beta) were added to modular estuarine mesocosms; the kinetics and degradation products from each mesocosm are reported. The persistent product endosulfan sulfate was generated in all cases; however, its yield was approximately a factor of three higher from alpha-endosulfan relative to beta-endosulfan. Beta-endosulfan hydrolyzed faster than alpha-endosulfan to endosulfan diol, which then rapidly degraded to endosulfan ether, endosulfan alpha-hydroxyether (major product), and endosulfan lactone. The ring-opened form of the lactone, endosulfan gamma-hydroxycarboxylate, is reported for the first time; it appears to be a terminal product, at least over the timescale of the experiment. The equilibrium between endosulfan gamma-hydroxycarboxylate and endosulfan lactone is dependent on pH, as only the protonated form of the gamma-hydroxy acid undergoes ring-closure. The pKa of the gamma-hydroxy acid was determined to be 5.7, implying that the lactone will quickly open and deprontonate under environmentally relevant conditions.

Biological Availability↗
PubMed2006

Isolation of a soil bacterium capable of biodegradation and detoxification of endosulfan and endosulfan sulfate.

Endosulfan, an endocrine disrupting chemical, is a widely used cyclodiene organochlorine pesticide worldwide, and it blocks neuronal GABA(A)-gated chloride channels in mammals and aquatic organisms. Endosulfan and its metabolites, such as endosulfan sulfate, are persistent in environments and are considered as toxic chemicals. For bioremediation of endosulfan, in this study, an attempt was made to isolate an endosulfan and endosulfan sulfate degrading bacterium from endosulfan-polluted agricultural soil. Through repetitive enrichment and successive subculture using endosulfan or endosulfan sulfate as the sole carbon source, a bacterium KS-2P was isolated. The KS-2P was identified as Pseudomonas sp. on the basis of the results of a 16S rDNA sequencing analysis and MIDI test. The degradation ratios for endosulfan or endosulfan sulfate in minimal medium containing endosulfan (23.5 microg mL(-1)) or endosulfan sulfate (21 microg mL(-1)) were 52% and 71%, respectively. Our results suggest that Pseudomonas sp. KS-2P has potential as a biocatalyst for endosulfan bioremediation.

Biodegradation, Environmental↗
PubMed2000

Genotoxic effects of alpha-endosulfan and beta-endosulfan on human HepG2 cells.

alpha-Endosulfan and ss-endosulfan are isomers of endosulfan, a pesticide used worldwide. In this study, we examined the genotoxicity of [alpha]- and ss-endosulfan in vitro with a HepG2 cell line. We used sister chromatid exchanges (SCE), micronuclei (MN), and DNA strand breaks as detected by single-cell gel electrophoresis (SCG) assays as biomarkers to judge the genotoxicity of [alpha]- and ss-endosulfan at concentrations from 1 times 10(-12) M to 1 times 10(-3) M. After treating HepG2 cells for 48 hr with ss-endosulfan, SCE showed a significant increase at concentrations from 1 times 10(-7) M to 1 times 10(-5) M, and MN showed a significant increase at concentrations from 5 times 10(-5) M to 1 times 10(-3) M. [alpha]-Endosulfan failed to show significant effects in both the SCE and MN assays. After treating HepG2 cells with [alpha]- or ss-endosulfan for 1 hr, DNA strand breaks were significantly induced by [alpha]-endosulfan at concentrations from 2 times 10(-4) M to 1 times 10(-3) M, and by ss-endosulfan at 1 times 10(-3) M. The results of this study suggest that both [alpha]- and ss-endosulfan are genotoxic to HepG2 cells and that the genotoxicity of ss-endosulfan seems stronger than that of [alpha]-endosulfan.

Biomarkers↗
PubMed2002

Klebsiella pneumoniae KE-1 degrades endosulfan without formation of the toxic metabolite, endosulfan sulfate.

For bioremediation of toxic endosulfan, endosulfan degradation bacteria, which do not form toxic endosulfan sulfate, were isolated from various soil samples using endosulfan as sole carbon and energy source. Among the 40 isolated bacteria, strain KE-1, which was identified as Klebsiella pneumoniae by physiological and 16S rDNA sequence analysis, showed superior endosulfan degradation activity. Analysis of culture pH, growth, free sulfate and endosulfan and its metabolites demonstrated that KE-1 biologically degrades 8.72 microg endosulfan ml(-1) day(-1) when incubated with 93.9 microg ml(-1) endosulfan for 10 days without formation of toxic endosulfan sulfate. Our results suggest that K. pneumoniae KE-1 degraded endosulfan by a non-oxidative pathway and that strain KE-1 has potential as a biocatalyst for endosulfan bioremediation.

Biodegradation, Environmental↗
PubMed2004

Induction of oxidative stress by endosulfan and protective effect of lipid-soluble antioxidants against endosulfan-induced oxidative damage.

The toxic mechanism of endosulfan, a widely used organochlorine pesticide, was investigated in Saccharomyces cerevisiae and human cell lines. A concentration-dependent inhibition of cell growth was observed when S. cerevisiae was exposed to endosulfan, and its cytotoxicity (IC(50)) was found to be 49 microM and 86 microM in HepG2 and HeLa human cell lines, respectively. The treatment of S. cerevisiae with endosulfan resulted in oxidative damage, as demonstrated by thiobarbituric acid-reactive substance (TBARS) production, in a dose-dependent manner, and the growth inhibition was recovered by treatment with lipid-soluble antioxidants, such as alpha-tocopherol or beta-carotene, suggesting that endosulfan toxicity may be closely associated with endosulfan-induced reactive oxygen species (ROS) generation. The inhibition of cellular respiration by endosulfan treatment and the recovery of respiration activity by antioxidant treatment confirmed that endosulfan induces oxidative stress and inhibits respiration via ROS generation. These results suggest that unicellular yeast might provide a useful system for elucidating the toxicity of endosulfan.

Antioxidants↗
PubMed1976

Collaborative study of the determination of endosulfan, endosulfan sulfate, tetrasul, and tetradifon residues in fresh fruits and vegetables.

A method for the determination of endosulfan I, endosulfan II, endosulfan sulfate, tetrasul, and tetradifon residues in fresh fruits and vegetables was studied collaboratively. The method consists of extraction of the product with acetonitrile, ether and elution from a Florisil column with mixtures of hexane, methylene chloride, and acetonitrile, and determination of the residues by electron capture gas-liquid chromatography. This method was studied by 8 collaborators, using apples and cucumbers as the samples. Each sample was spiked with 2 levels of each pesticide. The average per cent recoveries for apples and cucumbers, respectively were as follows: endosulfan I, 103.6 and 101.5; endosulfan II, 102.9 and 100.0; endosulfan sulfate, 100.9 and 92.9; tetrasul, 98.8 and 102.2; and tetradifon, 106.4 and 101.9. The method has been adopted as official first action.

Chlorobenzenes↗
PubMed2002

Volatilization of trifluralin, atrazine, metolachlor, chlorpyrifos, alpha-endosulfan, and beta-endosulfan from freshly tilled soil.

The volatile and soil loss profiles of six agricultural pesticides were measured for 20 days following treatment to freshly tilled soil at the Beltsville Agricultural Research Center. The volatile fluxes were determined using the Theoretical Profile Shape (TPS) method. Polyurethane foam plugs were used to collect the gas-phase levels of the pesticides at the TPS-defined critical height above a treated field. Surface-soil (0-8 cm) samples were collected on each day of air sampling. The order of the volatile flux losses was trifluralin > alpha-endosulfan > chlorpyrifos > metolachlor > atrazine > beta-endosulfan. The magnitude of the losses ranged from 14.1% of nominal applied amounts of trifluralin to 2.5% of beta-endosulfan. The daily loss profiles were typical of those observed by others for volatile flux of pesticides from moist soil. Even though heavy rains occurred from the first to third day after treatment, the majority of the losses took place within 4 days of treatment, that is, 59% of the total applied atrazine and metolachlor and >78% of the other pesticides. Soil losses generally followed pseudo-first-order kinetics; however, leaching due to heavy rainfall caused significant errors in these results. The portion of soil losses that were accounted for by the volatile fluxes was ordered as follows: alpha-endosulfan, 34.5%; trifluralin, 26.5%; chlorpyrifos, 23.3%; beta-endosulfan, 14.5%; metolachlor, 12.4%; and atrazine, 7.5%.

Acetamides↗
PubMed1981

Gas-liquid chromatographic-mass spectrometric confirmation of endosulfan and endosulfan sulfate in apples and carrots.

A gas-liquid chromatography-mass spectrometric (GLC-MS) procedure is described for the confirmation of endosulfan I, endosulfan II, and endosulfan sulfate in apples and carrots. After extraction, cleanup, and determination by electron capture gas-liquid chromatography using current AOAC methodology, residues are confirmed by GLC-MS. The chemical ionization (CI) mode is used with methane as a reagent gas. Each residue is confirmed by a scan of only 4 regions of its mass spectrum rather than the full mass range. The 4 mass regions for the 2 endosulfan isomers are 274-280, 340-346, 368-374, and 404-412 atomic mass units (amu). For endosulfan sulfate, the mass regions are 286-294, 322-330, 384-392, and 420-428 amu. Four ions and their chlorine isotopic distributions are detected for each compound by this scanning technique. This method was developed by using carrots and apples to which had been added 0.1 ppm (50% of the current legal tolerance on carrots) of each of the 3 pesticides. The gas chromatographic retention times and the mass spectra of the 4 mass regions specified for the 3 pesticides were compared to those of reference standards injected under identical GLC-MS conditions and were used as the basis for confirming identity of the 3 compounds.

Endosulfan↗
PubMed2002

Analysis of endosulfan isomers and endosulfan sulfate in air and tomato leaves by gas chromatography with electron-capture detection and confirmation by gas chromatography-mass spectrometry.

Rapid analytical methods for the determination of endosulfan isomers and endosulfan-sulfate in air and plant samples were developed. The insecticides were trapped from air using a column containing Florisil and extracted with a low volume of ethyl acetate, assisted by sonication. Pesticide residues were determined by gas chromatography with electron-capture detection using a nonpolar capillary column. Residue identities were confirmed by gas chromatography coupled with mass spectrometry. Recoveries of these compounds from air samples were always higher than 78% with an RSD lower than 11% and the detection limits obtained were at least 0.3 ng/l air. Leaf samples were homogenised with ethyl acetate and extracts cleaned-up on an aluminium oxide column. Pesticides were eluted with a hexane-ethyl acetate (80:20, v/v) mixture. Recoveries obtained from plant samples were higher than 78% with an RSD lower than 14% and detection limits in leaves were 0.02 microg/g for each pesticide. These methods were applied to study the volatilisation of endosulfan from tomato leaves under laboratory conditions. A volatilisation rate near 1% of the initial amount of endosulfan per hour was obtained during the first 24 h at room temperature.

Air↗
PubMed2003

Determination of endosulfan isomers and endosulfan sulfate in tomato juice by matrix solid-phase dispersion and gas chromatography.

A rapid method based on matrix solid-phase dispersion was developed for the determination of endosulfan isomers and endosulfan sulfate in commercial tomato juice. After the optimisation of different parameters such as the type of adsorbent, the extraction solvent, and the extraction assistance by sonication, the recoveries obtained ranged from 81 to 100% with relative standard deviations equal to or lower than 10%. The analysis of samples was accomplished using gas chromatography with electron-capture detection and the identity of endosulfan residues was confirmed by gas chromatography-mass spectrometry with selected ion monitoring. The detection limit for these compounds, calculated as three times the background noise, was 1 microg/kg. The proposed method was applied to the analysis of these compounds in commercial juice samples and levels of endosulfan between 1 and 5 microg/kg were detected in some samples.

Beverages↗
PubMed2003

Unintentional toxicity due to endosulfan: a case report of two patients and characteristics of endosulfan toxicity.

Unrestricted use of endosulfan, a cyclic chlorinated hydrocarbon insecticide, results in many intentional and unintentional toxicities in Turkey. Due to its chemical stability in the environment, toxicity may be seen even if exposure happens 6-mo after the endosulfan has been sprayed. We discuss a case of 2 patients with unintentional exposure to endosulfan after eating contaminated foods, one of which presented with neurological manifestations and required mechanical ventilation, the other having only mild symptoms. Because of the toxicity to humans and threats for nature, use of endosulfan should be restricted or banned.

Coma↗
PubMed1984

Toxicity of endosulfan: distribution of alpha- and beta-isomers of racemic endosulfan following oral administration in rats.

Endosulfan was administered orally (2.5 and 7.5 mg/kg) daily to male rats for a period of 60 days. The distribution pattern of alpha and beta-isomers was studied using a gas-liquid chromatograph equipped with an electron capture detector. There was a significant increase in liver and lung weights. The testes weight was slightly decreased. No significant change in weights of other tissues was observed. At both dose levels, the concentration of alpha-isomer was highest in kidney (574 and 1655 ng/g, respectively), followed by lung, ventral prostate, spleen, testes and brain. In the seminal vesicle, epididymis, heart and liver, the concentration of beta-isomer was higher than the alpha-isomer. The results of the study indicated a differential ability to accumulate the two isomers of endosulfan which may help to explain the difference in the toxic potential of the alpha- and beta-isomers.

Administration, Oral↗