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PubMed1991

Characterization of the epoxide hydrolase from an epichlorohydrin-degrading Pseudomonas sp.

An epoxide hydrolase was purified to homogeneity from the epichlorohydrin-utilizing bacterium Pseudomonas sp. strain AD1. The enzyme was found to be a monomeric protein with a molecular mass of 35 kDa. With epichlorohydrin as the substrate, the enzyme followed Michaelis-Menten kinetics with a Km value of 0.3 mM and a Vmax of 34 mumol.min-1.mg protein-1. The epoxide hydrolase catalyzed the hydrolysis of several epoxides, including epichlorohydrin, epibromohydrin, epoxyoctane and styrene epoxide. With all chiral compounds tested, both stereoisomers were converted. Amino acid sequencing of cyanogen bromide-generated peptides did not yield sequences with similarities to other known proteins.

Amino Acid Sequence↗
PubMed1996

Toxicity studies of epichlorohydrin in Sprague-Dawley rats.

Adult male and female Sprague-Dawley rats received epichlorohydrin via gavage in distilled water for 10 consecutive days at dose levels of 3, 7, 19, and 46 mg/kg-day, and for 90 days at dose levels of 1, 5, and 25 mg/kg-day. Epichlorohydrin did not adversely effect mortality, but toxicity, at the higher doses, was evident by: 1) losses in body weight gain and organ weights, 2) reductions in food and water consumption, and 3) in the hematological and microscopic examinations in both study periods. Significant decreases in erythrocyte count, hemoglobin, and hematocrit levels were found in the high dose level in males after 10 and 90 days. Dose-related increases in kidney and liver weights were observed in both sexes at 25 mg/kg-day in the 90-day study and in various organs for both 19 and 46 mg/kg-day in the 10-day study. Histopathological examination identified the forestomach as the primary target organ for both sexes and in both studies with significant dose-related increases in mucosal hyperplasia (acanthosis) and hyperkeratosis. Based on the data presented, a lowest observable adverse effect level (LOAEL) for oral exposure of Sprague-Dawley rats to epichlorohydrin is 3 mg/kg-day for 10 days and 1 mg/kg-day is suggested as the no observed adverse effect level (NOAEL) for a 90 day oral exposure. These conclusions were the same whether the lesions were analyzed for each sex individually or whether the data in each study was pooled.

Administration, Oral↗
PubMed2003

[Studies on the analytical method for epichlorohydrin from internal can coatings].

An improved migration test was developed for determination of trace amounts of epichlorohydrin from internal can coatings. Eight kinds of sample cans, coated mainly with epoxy resin, for foods and beverages were prepared, and both their bodies and lids were tested for migration as follows. A body was filled with n-pentane and soaked for 2 hours at 25 degrees C. A lid was soaked in n-pentane (2 mL/cm2) for 2 hours at 25 degrees C. The test solution was analyzed by GC-FID and GC/MS using two DB-WAX capillary columns with different inside diameters. The limits of quantitation were 0.05 microgram/mL by GC-FID and 0.02 microgram/mL by GC/MS with selected ion monitoring. Recoveries of spiked epichlorohydrin were 99.9-104.5% at the level of 0.05 microgram/mL and 0.5 microgram/mL, with high precision. In this study, no epichlorohydrin was found to have migrated from any of the bodies and lids.

Chromatography, Gas↗
PubMed1986

Stability of 7-alkyldeoxyguanosines of trichloropropylene oxide, epichlorohydrin and glycidol.

Deoxyguanosine was reacted with trichloropropylene oxide (TCPO), epichlorohydrin and glycidol in aqueous solution and the products were isolated by high pressure liquid chromatography (HPLC). For each compound 7-alkyldeoxyguanosine was the main adduct; TPCO reacted about 3 times faster than epichlorohydrin and about 10 times faster than glycidol. The pKa's of the 7-alkyldeoxyguanosines were 6.7, 6.8 and 6.9 for the TCPO-, epichlorohydrin-, and glycidol-adducts, respectively. The respective half-lives of imidazole ring-opening were 6.3, 15 and 27 hrs (pH 8.5, 28 degrees) and those of depurination 1.9, 3.4 and 4.4 hrs (pH 5.5, 28 degrees).

Alkylation↗
PubMed1983

In vivo and in vitro mutagenicity studies of a possible carcinogen, trichloroethylene, and its two stabilizers, epichlorohydrin and 1,2-epoxybutane.

In vivo and in vitro methodologies that have employed the yeast Schizosaccharomyces pombe as genetic indicator have been utilized to investigate the mutagenicity of two trichloroethylene (TCE) samples of pure and technical grade. Mutagenicity assays were also performed on two stabilizers contained in the technical grade sample: epichlorohydrin and 1,2-epoxybutane. In the in vitro studies a metabolic conversion system was supplied by liver homogenate (S-9) from mice and rats untreated and pretreated with phenobarbital and/or beta-naphthoflavone. Up to highly toxic doses of TCE were applied to growing and stationary-phase yeast cells. In the in vivo studies two different host-mediated assays, intrasanguineous and intraperitoneal methodologies, were performed on different mice breeds treated by oral administration. Epichlorohydrin and epoxybutane were tested singly or combined in a mixture of the same ratio as in the technical grade TCE sample. Both TCE samples gave negative results for in vivo and in vitro assays, whereas the two contaminants were found mutagenic only in vitro. The high toxicity of the technical TCE sample did not allow us to reach concentrations containing effective levels of its two additives.

Animals↗
PubMed2003

Pulmonary function abnormality and respiratory tract irritation symptoms in epichlorohydrin-exposed workers in Taiwan.

BACKGROUND: Epichlorohydrin (ECH) is a strong irritant of the eyes, respiratory tract, and skin. The aims of this study were to examine the dose-response relationship between observed abnormal pulmonary function tests and respiratory tract irritation symptoms among epichlorohydrin-exposed workers in Taiwan. METHODS: A total of 167 workers were randomly selected from a resin synthesis factory. Sixty-six air samples were taken to determine ECH concentration in the workplace. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed. RESULTS: There were 13 of 41 (31.7%) abnormal mean mid-expiratory flow (MMEF) among the high-ECH-exposed workers, 11 of 38 (29%) among the low-ECH-exposed workers, and 4 of 59 (6.8%) among non-ECH-exposed workers. There was a significant linear trend between ECH exposure and the prevalence of small airway abnormalities (P = 0.007) after adjusting for other factors. There was also a significant dose-response relationship of respiratory tract irritation symptoms (cough, phlegm, chest tightness, and dyspnea) among the ECH-exposed workers. CONCLUSIONS: This study suggests that obstructive lung abnormalities and small airway lung damage are associated with ECH exposure. The study also suggests that exposure to very low concentrations (<0.2 ppm) causes significant higher prevalence of respiratory tract irritation symptoms. Causal inferences from the findings cannot be made from this cross-sectional study and further longitudinal studies are needed to better clarify the nature of the observed associations.

Adult↗
PubMed2001

Mass spectrometric identification of a candidate biomarker peptide from the in vitro interaction of epichlorohydrin with red blood cells.

The reaction products of epichlorohydrin with human alpha- and beta- globins, obtained through in vitro incubation of these compounds and red blood cells, were determined by using reversed-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization tandem mass spectrometry. The alpha-globin was much more reactive than the beta-globin. At low incubation ratios, approximating the order of magnitude of epichlorohydrin concentration as found in workplaces, the only modified peptide still detectable was the 62-90 belonging to the alpha-chain and carrying an incremental mass of 92 u on either His72 or His89. Given that the two peptides co-eluted in a single chromatographic peak during RP-HPLC separation, they could be chosen as suitable biomarkers for quantification in the setting up of a new methodology for the biological monitoring of persons occupationally exposed, replacing currently known procedures.

Amino Acids↗
PubMed1983

Inhalation toxicity of epichlorohydrin: effects on fertility in rats and rabbits.

The effects of inhaled epichlorohydrin (ECH) on the fertility of Sprague-Dawley rats and New Zealand white rabbits were studied. Groups of 10 male rabbits, 30 male rats, and 30 female rats were exposed to 0, 5, 25, or 50 ppm of ECH vapor for 6 hr/day, 5 days/week for 10 weeks, and were held for a 10-week postexposure females. Exposed male rats were mated with unexposed females at several intervals during and after the exposure period. In addition, female rats which had been exposed for the 10-week period were mated with unexposed males and allowed to deliver their young. Exposure to 50 ppm of ECH vapor for 10 weeks resulted in transient infertility in the male Sprague-Dawley rats; recovery of fertility in rats occurred during the second week after termination of exposure. Male rats exposed to 25 ppm of ECH were able to impregnate unexposed females; however, fewer implantations were observed in these females than in the females mated to control males suggesting that fertility was adversely affected in this group as well. This effect also was reversed by the second week following termination of exposure. The incidence of resorptions in the unexposed female rats which were bred to the exposed males was not adversely affected. Among female rats exposed to ECH, no adverse effects were observed on estrus cycle, pregnancy rate, parturition, or the number and viability of the offspring. No discernible effects were noted on the volume of the ejaculate or on the motility, viability, concentration, or fertility of spermatozoa from male rabbits exposed to up to 50 ppm of ECH. Histologic examination of tissues from an interim and final termination of the exposed animals indicated that the most severely affected organ following inhalation exposure to 25 or 50 ppm of epichlorohydrin in both rats and rabbits was the nasal turbinates. These lesions, interpreted to be a result of irritation from the test material, were no longer present in animals which were held for the 10-week postexposure period. No adverse effects were observed among rats or rabbits exposed to 5 ppm of ECH for 10 weeks.

Animals↗
PubMed1991

The effect of deuterium labeling on the genotoxicity of N-nitrosodimethylamine, epichlorohydrin and dimethyl sulfate.

Deuterated and non-deuterated N-nitrosodimethylamine, epichlorohydrin and dimethyl sulfate were evaluated for the ability to induce DNA single-strand breaks in rat hepatocytes as measured by alkaline elution. Non-deuterated nitrosodimethylamine induced twice the amount of DNA-strand breaks as the deuterated form. No evidence of a deuterium isotope effect was seen for the direct-acting alkylating agents epichlorohydrin and dimethyl sulfate.

Animals↗
PubMed1998

Solid state NMR spectroscopy study of molecular motion in cyclomaltoheptaose (beta-cyclodextrin) crosslinked with epichlorohydrin.

Dry and hydrated insoluble cyclomaltoheptaose (beta-cyclodextrin, beta-CD) polymers have been investigated by solid state 13C NMR spectroscopy techniques such as cross polarization/magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning both with (DD-MAS) and without (MAS) dipolar decoupling and CP/MAS dipolar dephasing (dd-CP/MAS) to allow the assignment of the main 13C signals. In the solid state, the presence of water in the samples resulted in a better resolution reflecting increased mobility. Two distinct components (crosslinked beta-CD and polymerized epichlorohydrin) have been found. The molecular mobility of these two components has been analyzed in terms of relaxation parameters such as 13C spin lattice relaxation (T1) and 1H spin lattice relaxation in the rotating frame (T1 rho). The T1 values of the polymers show that the beta-CD trapped inside the polymers does not seem to undergo changes in its mobility whatever the amount of epichlorohydrin. The addition of water to beta-CD significantly increases the T1 values reflecting strong interaction between beta-CD and the solvent. The T1P values obtained reflect the homogeneous nature of the materials.

Carbohydrate Sequence↗
PubMed2002

Revision of absolute configuration of enantiomeric (methylenecyclopropyl)carbinols obtained from (R)-(-)- and (S)-(+)-epichlorohydrin and methylenetriphenylphosphorane. Implications for reaction mechanism and improved synthesis of antiviral methylenecyclopropane analogues of nucleosides.

Absolute configurations of enantiomeric methylenecyclopropanecarbinols obtained by reaction of (R)- and (S)-epichlorohydrin 5 with methylenetriphenylphosphorane or resolution of the corresponding oxaphospholane 6 via a salt with L-(+)-tartaric acid and subsequent Wittig transformation with formaldehyde were revised. The (-)-oxaphospholane 6 has the S,S and (-)-(methylenecyclopropyl)carbinol (4) the R configuration. The configurations of (+)-6 and (+)-4 are then R,R and S, respectively. These assignments are in accord with an initial attack of phosphorane at the oxirane ring of epichlorohydrin. An improved preparation of key enantiomeric intermediates (R)-1a and (S)-1a, important for synthesis of antiviral purine methylenecyclopropane analogues of nucleosides, is also described.

Adenine↗
PubMed1983

Reactions of methylnitrosourea, epichlorohydrin, styrene oxide and acetoxyacetylaminofluorene with polyamino acids.

Radioactive methylnitrosourea, epichlorohydrin, styrene oxide, and N-acetoxy-2-acetylaminofluorene were reacted with 14 different polyamino acids in vitro, to determine the relative reactivity of the functional groups in amino acids. All the carcinogens reacted preferentially with polycysteine and much less with polyhistidine. Reaction was also noted with polylysine, polymethionine and polyarginine, as well as with DNA. Epichlorohydrin and styrene oxide reacted also with polyserine. Methylnitrosourea and N-acetoxy-2-acetylamino-fluorene reacted relatively more with polyhistidine as compared with the epoxides. Polycysteine, polyhistidine and polylysine were more reactive towards styrene oxide at pH 8 than at pH 6.

2-Acetylaminofluorene↗
PubMed2006

A convenient method for epichlorohydrin determination in water using headspace-solid-phase microextraction and gas chromatography.

A simple procedure for epychlorohydrin determination in water is presented. In order to optimize the epichlorohydrin extraction conditions in water using headspace (HS)-solid-phase microextraction (SPME), followed by gas chromatography, an experimental design in two steps is performed. Firstly, a 2(5-2) fractional factorial design for screening the significant variables is used. Secondly, a central composite design for optimizing them is carried out. The best experimental conditions are the followings: poly(dimethysiloxane)-divinylbenzene coating fiber; 20 min extraction time; 5 degrees C extraction temperature; 300 g/L sodium chloride; and 20 mL HS volume in a 40-mL vial. Using the previous extraction conditions with gas chromatography (GC)-flame ionization detection equipment, a limit of detection (LOD) of 1.8 microg/L and a relative standard deviation (RSD) of 3.8% (for 25 microg/L) are obtained. With a GC electron capture detection equipment the RSD is 6.6% (for 5 microg/L), and the LOD found is lower (0.08 microg/L). The method is applied to the analysis of water from four treatment plants at the entrance and effluent stream. The standard addition method is used to quantitate the epichlorohydrin that is found in the raw water of the three wastewater treatment plants.

Chromatography, Gas↗
PubMed1979

Activation of Sepharose with epichlorohydrin and subsequent immobilization of ligand for affinity adsorbent.

The optimal conditions for the activation of Sepharose by epichlorohydrin and subsequent immobilization of ligands were investigated. Under the optimal conditions for activation, namely, 30% Sepharose-5% epichlorohydrin-0.4 M NaOH, 40 degrees C, 2 h, the maximum amount of epoxy group was introduced into Sepharose with low cross-linking. The absorbents obtained by using N-acetyl-D-glucosamine, tri-N-acetylchitotriose, and glycoprotein as a ligand exhibited no nonspecific adsorption and good permeability for the high molecular substance to be purified, and were stable in an alkaline solution. Solanum tuberosum agglutinin was specifically adsorbed on a tri-N-acetylchitotriose-Sepharose column and was quantitatively recovered by elution with 0.2 M ammonia solution. Furthermore, the column could be repeatedly used under these conditions without reduction of its capacity.

Acetylglucosamine↗
PubMed1986

Sensitization to epichlorohydrin and epoxy system components.

In an epoxy resin manufacturing plant, 26 of 228 (11.4%) workers had work-related eruptions; 19 were patch tested. The test series consisted of chemicals used in the manufacturing process, a standard battery and some other sensitizers. The prevalence of sensitization to epichlorohydrin and/or epoxy resins in the whole group was 6.1%. A relatively high prevalence (3.5%) of epichlorohydrin sensitization was found. 10 cases of sensitization to liquid epoxy resin (MW about 385) were observed, in 7 cases combined with allergy to solid epoxy resin (MW 980). Sensitization to Bisphenol A was not seen.

Adult↗
PubMed1978

Tissue distribution and excretion of 14C-epichlorohydrin in male and female rats.

The tissue distribution and excretion of 14C-epichlorohydrin was studied in both male and female rats following an oral dose of 10 mg/kg. Organs containing the highest concentrations of radioactive label per unit weight were the kidneys, liver, pancreas, ann spleen. With the exception of the pancreas, these are the same organs in which epichlorohydrin-induced pathologic changes have been reported by a number of investigators, indicating a direct correlation between tissue levels and target organ toxicity. The principal route of excretion was via the kidneys, 38-40% of the dose appearing in the urine during the 72 hour period of study. Fecal excretion was relatively insignificant, representing less than 4% of the administered dose. It was found that 18-21% of the administered dose appeared as 14CO2 in the expired air, the majority being excreted in the first 4 hours, suggesting a rapid and extensive biotransformation of the compound.

Animals↗
PubMed2004

Montmorillonite intercalated with polyaminoamide-epichlorohydrin: preparation, characterization, and sorption behavior.

Organophilic and cationic montmorillonite is desirable for pitch control in the pulp and paper industry. In this paper, polyaminoamide-epichlorohydrin (PAE)-modified montmorillonite was prepared via either solution intercalation or melt intercalation of polyaminoamide into montmorillonite, followed by the reaction with epichlorohydrin. The modified montmorillonite samples were characterized by FTIR spectroscopy, X-ray diffraction, and thermal gravimetric analysis. The amount of PAE intercalated and the surface charge densities of cationic-modified montmorillonite were determined. It was found that melt intercalation appeared to be more effective in the inclusion of PAE than solution intercalation. However, both solution- and melt-intercalated samples with various surface charge densities exhibited strong affinity toward dispersed colloidal rosin acid.

Journal Article↗
PubMed2006

Ab initio determination of optical rotatory dispersion in the conformationally flexible molecule (R)-epichlorohydrin.

Ab initio optical rotation data from linear-response coupled-cluster and density-functional methods are compared to both gas-phase and liquid-phase polarimetry data for the small, conformationally flexible molecule epichlorohydrin. Three energy minima exist along the C-C-C-Cl dihedral angle, each with strong, antagonistic specific rotations ranging from ca. -450 to +500 deg/[dm (g/mL)] at 355 nm. Density-functional theory (specifically the B3LYP functional) consistently overestimates the optical rotations of each conformer relative to coupled-cluster theory (in agreement with our earlier observations for conformationally rigid species), and we attribute this to density-functional theory's underestimation of the lowest-lying excitation energies of epichlorohydrin. Length- and velocity-gauge formulations of the coupled-cluster response function lead to slightly different specific rotations (ca. 7% at short wavelengths). We have determined well-converged Gibbs free energy differences among the conformers using complete-basis-set extrapolations of coupled-cluster energies including triple excitations to obtain Boltzmann-averaged specific rotations for comparison to the gas-phase results. The length-gauge coupled-cluster data agree remarkably well with experiment, with the velocity-gauge coupled-cluster and density-functional data bracketing the experimental results from below and above, respectively. Liquid-phase conformer populations reported earlier by Polavarapu and co-workers from combined infrared absorption and theoretical analyses differ markedly from the gas-phase populations, particularly for polar solvents. Nevertheless, Boltzmann-averaged specific rotations from both coupled-cluster and density-functional calculations agree well with the corresponding experimental intrinsic rotations, although the theoretical specific rotations for the individual conformers do not take solvent effects into account. PCM-based estimates of conformer populations lead to poor agreement with experiment.

Journal Article↗