• Environmental Mutagens and Carcinogens
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• v.17 no.2
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• pp.97-108
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• 1997

The drugs or xenobiotics introduced to the body, are detoxified through the process of biotransformation in the body. In this process, most of the insoluble compounds become more polar, soluble and easily excretable. But, parts of introduced materials are metabolized to highly reactive electrophilic carcinogens through activation pathways. These metabolites are toxic and can react with DNA, RNA and proteins which are nucleophilic compounds. The objective of this study is to illustrate the aleactivation pathways of two highly reactive epoxide compounds, vinyl carbamate epoxide (VCO) and 2'-(4-nitrophenoxy)oxirane (NPO). They are the ultimate electrophilic carcinogens of ethyl carbamate(urethane) and 4-nitrophenyl vinyl ether, respectively. In this research, we studied the inhibition of the mutagenic activities of VCO or NPO by nuchieophiles [glutahione(GSH) and N-acetylcysteine(NAC)], detoxifying enzymes[epoxide hydrolase and glutathione-S-transferase(GST)] and intracellular organelles (microsomes and cytosol). In addition we also tested the suppression of DNA adducts formation by GSH and NAC. The results are summerized as follow. 1. The microsomes and cytosol which contain epoxide hydrolase and GST, respectively, decreased the mutagenicity of VCO (74% and 95%, respecfivel), and NPO (35% and 93%, respectively). The nucleophilic GSH and NAC decreased the mutagenicity by 86% (VCO) and 80% (NPO), 76% (VCO) and 40% (NPO), respectively. 2. The purified epoxide hydrolase decreased the mutagenicity of two epoxides in a dose-dependent manner, and GSH also decreased the mutagenicity in the presence of GST. 3. Formation of two DNA adducts, 7-(2'-oxoethyi)guanine (OEG) and N2,3-ethenoguanine(EG), were compared in the presence of calf thymus DNA and epoxide (VCO or NPO) in vitro system. The amounts of DNA adducts were decreased in the presence of GSH (25% and 29% in VCO, 32% and 29% in NPO), and NAC (14% and 16% in VCO, 21% and 11% in NPO), respectively. From these results, it is concluded that the ultimate carcinogenic metabolites, VCO and NPO, can be made in the body, but much of them may be inactivated and detoxified by the nucleophilic GSH, NAC and detoxifying enzymes (epoxide hydrolase and GST). Therefore, by these mechanism, the formation of DNA adducts and mutagenic activities of these two epoxides may be lowered in vivo.

• Journal of Sericultural and Entomological Science
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• v.39 no.1
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• pp.17-21
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• 1997

Oral application of fenoxycarb, O-ethyl N-(2-(4-phenoxyphenoxy)ethyl) carbamate, the commercial formulation Insegar, on the 1st day of the 3rd instar made no difference in the egg laying and the hatchability as compared to 750 grains for the number of eggs laid, 53 grains for the number of the resideual eggs unlaid, 749 grains for the number of fertirized eggs, 97% for the total hatchability, and 95% for the useful hatchability as in the control but on the first day of the 4th instar, the number of the remainder eggs in the ovary increased by 2.4 folds, and reduced number of the eggs laid, number of unfertilized eggs, the hatchabillity and useful hatchability by 39%, by 66%, by 68% and by 72%, respectively. When diluted Insegar was applied topically every other two days from the pupae to the moth at concentration of 10-6, 10-7, 10-8, 10-9, 10-10 the number of eggs laid, the number of the unfertilized eggs, the total hatchability and the useful hatchability were decreased. More severe decrease took place as concentration lowered and the earlier application.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.203-211
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• 2007

This study was conducted in cut rose cultivation field in Goyang to evaluate pesticide exposure of farmers and the relationship between the exposure and work environment/method for cut rose farmers. Dermal exposure was assessed with patch (thin chromatography layer paper), cotton glove by body parts during mixing and spraying works in which pyrethroid, organophosphate, carbamate pesticide were used in 4 cut rose greenhouses located in Goyang province, checking characteristics of environment/working method at the same time. Body parts assessed were as follows ; glove : hand, patch : head, neck(front/back), chest, back, shoulder(right/left), upperarm(right/left), forearm(right/left), thigh(right/left), shin(right/left). Pesticides were analyzed using gas chromatography(NPD/FID) after extracting with ethyl acetate. Exposure amount differed according to pesticide type. But after standardizing with total net weight of pesticide sprayed, there were no significant difference among pesticides. There were significant difference in exposure amount among body parts(especially exposure amount of thigh, shin were more than the others), which means exposure happen not by pesticide dispersion in air but by contact with cut rose(leaf, branch) indirectly. Walking forward during spraying made farmers more exposed than waling backward, these results means contacts with leaves/branches made exposure happen in cut rose greenhouse also. As a result, pesticide exposure in cut rose greenhouse was related with contact of leaf/branch which pesticide remained in, which made exposure pattern (especially exposure amount) differ by body parts

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.63-68
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• 2013

Ethyl carbamate (EC) is a contaminant generated in the fermentation processes of various fermented foods. In this study, residue levels of EC in 95 alcoholic beverage samples were determined by using Gas Chromatography/Tandem Mass Spectrometry (GC/MS/MS). All the samples were purified by a liquid-liquid extraction (LLE) method using dichloromethane. The LLE method enables an improvement in time and cost to detection and specificity over the conventional extraction methods. The limits of detection and quantification (LOD and LOQ) to analyze EC were 1.3 and 4.0 ng/mL, respectively. The recovery rates of EC were ranged from 90.0 to 97.5% at the levels of 50, 100, and 500 ug/L. Among traditional grain-based alcoholic beverage samples (n = 34), the average residue levels of EC in takju, yakju, and cheongju were 0.63, 7.01, and 14.11 ug/L, respectively. Among fruit-based alcoholic beverage samples (n = 48), those of EC in japanese apricot spirits, bokbunjaju, grape wines, and other fruit wines were 79.18, 1.66, 2.64, and 2.39 ug/L, respectively. Among distilled or diluted alcoholic beverage samples (n = 13), those of EC in soju (distilled or diluted), general distillates, liquors, and brandies were 0, 3.30, 8.20, and 8.52 ug/L, respectively. Therefore, this study reports that the residue levels of EC in the alcoholic beverages, distributed in the current domestic markets, did not reach its maximum allowed levels of 30 and 400 ug/L established for grape and fruit wines in Canada, respectively.

• Food Science and Preservation
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• v.19 no.2
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• pp.308-314
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• 2012

Two hundred and twenty three yeast strains were randomly isolated from Korean traditional $nuruk$. Among them, six urease producing yeast strains (designated JJA, JJB, JJ22, SHA, SHC and SH10) were selected on the Christensen urea agar plates. They showed the same pattern in the PCR-RFLP analysis of the ITS I-5.8S-ITS II region digested with $Hae$III and $HinF$1 restriction endonucleases. Its DNA sequences showed 100% (strains SHA, SHC and SH10) and 99.8% (strains JJA, JJB and JJ22) identity with those of $Issatchenkia$ $orientalis$ type strain ATCC 24210. Phylogenetic analysis resulted in that all the strains were closely related to $I.$ $orientalis$. Two representative strains, JJ22 and SH10, showing the highest urease activities were selected for further characterization. Their morphological, physiological and biochemical characteristics were also the same as $I.$ $orientalis$. Therefore, both the two strains were identified as $I.$ $orientalis$. They could grow at a wide range of temperature between $20-40^{\circ}C$ as well as pH between 2.0 and 10.0. However, a higher level urease activity were obtained at acidic pH than that at alkalic pH. The maximal level of urease activity was obtained at $30^{\circ}C$ (strain SH10) or $35^{\circ}C$ (strain JJ22) and in a liquid medium adjusted to the initial pH 5.0.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.237-248
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• 2006

Forty one compounds such as ester, sulfonyl ester, carbamate, ether and phosphoyl ester derivatives of thymol(I) and carvacrol(II) were synthesized. These derivatives were identified by IR, GC/MS and $^1H$-NMR spectra. Their antifungal activities were tested against various plant pathogenicfugi. Among them, several compounds were showed potent in vivo antifungal activities. The selected compounds showing in vitro antifungal activities were tested in vivo antifungal activities aganint 5 plant diseases such as rice blast, rice sheath blight, tomato late blight, cucumber anthracnose, and cucumber gray mold. As a result, 2-isopropyl-5-methylphenylacetate(I-1a) effectively suppressed the development cucumber gray mold and rice blast. Methyl(2-isopropyl-5-methylphenoxy)acetate(I-6d) and ethyl 4-(5-methyl-2-isopopylphenoxy)crotonate(I-7d) also showed potent in vivo antifungal actively againt rice sheath blight and tomato late blight, respectively.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.427-431
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• 1997

A simultaneous and rapid gas chromatographic determination of organophosphorus, organo-chlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The pesticides were extracted from samples with acetone by automated soxhlet apparatus and this extract was evaporated to dryness. The residue was dissolved in hexane, the solvent was applied to a Sep-Pak florisil catridge, was eluted with 50% ethyl acetate in n-hexane, and was injected to dual GC-ECD/NPD system. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. Except for dichlorvos and captan, recoveries of 46 pesticides were over 60%.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.721-727
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• 1998

An analytical method for simultaneous and rapid determination of organophosphorus, organochlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The analysis is performed by gas chromatograph with mass selective detector (GC/MSD) in selected ion monitoring (SIM) mode. Pesticides were extracted from samples with acetone by automated Soxhlet apparatus and this extract was evaporated to dryness for the analysis. The residue was dissolved in hexane, followed by a treatment with a Sep-Pak florisil catridge. Pesticides were positively confirmed by GC/MS, retention times, and ion ratios. This analytical method allows a rapid, reliable, and a good recovery of hydrophilic pesticides. Except far captafol, captan, dichlofluanid and dichlorvos, recoveries of 42 pesticides were over 70%.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1257-1257
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• 2001

Fourier transform near infrared (FT-NIR) spectroscopy was used as a rapid method to measure the $^{o}Brix$ content and to discriminate between different must samples in terms of their fee amino nitrogen (FAN) values. FT-NIR spectroscopy was also used as a rapid method to discriminate between Chardonnay wine samples in terms of the status of the male-lactic fermentation (MLF). This was done by monitoring the conversion of malic to lactic acid and thereby determining whether MLF has started, is underway or has been completed followed by classification of the samples. Furthermore, FT-NIR spectroscopy was applied as a rapid method to discriminate between table wine samples in terms of the ethyl carbamate (EC) content. EC in wine can pose a health threat and need to be monitored by determining the EC content in relation to the regulatory limits set by the authorities. For each of the above mentioned parameters, $QUANT+^{TM}$ methods were built and calibrations derived and it was found that a very strong correlation existed in the sample set for the FT-NIR spectroscopic predictions of $^{o}Brix$ (r = 0.99, SECV = 0.306), but the correlations for the FAN (r = 0.61, SECV = 272.1), malic acid (r = 0.58, SECV = 1.06), lactic acid (r = 0.51, SECV = 1.14) and EC predictions (r = 0.47, SECV = 3.67) were not as good. Soft Independent Modeling by Class Analogy (SIMCA) diagnostics and validation was applied as a sophisticated discrimination method. The must samples could be classified in terms of their FAN values when SIMCA was applied, obtaining results with recognition rates exceeding 80%. When SIMCA diagnostics and validation were applied to determine the progress of conversion of malic to lactic acid and the EC content, again results with recognition rates exceeding 80% were obtained. The evaluation of the applicability of FT-NIR spectroscopy measurement of FAN, $^{o}Brix$ values, malic acid, lactic acid and EC content in must and wine shows considerable promise. FT-NIR spectroscopy has the potential to reduce the analytical times considerably in a range of measurements commonly used during the wine making process. Where conventional FT-NIR calibrations are not effective, SIMCA methods can be used as a discriminative method for rapid classification of samples. SIMCA can replace expensive, time-consuming, quantitative analytical methods, if not completely, at least to some extent, because in many processes it is only needed to know whether a specific cut off point has been reach or not or whether a sample belongs to a certain class or not.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.169-178
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• 1984

This experiment was conducted to find out selective herbicides which are safe to the rice seedlings and to provide effective weed control method in protected semi-irrigated rice seedbed. There was no crop injury in rice with benzophenap [2-(4-2, 4-dichloro-3-methylbenzoyl)-1, 3-dimethyl-pyrazol-5-yl-oxy)-4'-methyl acetophenone] (240g), pyrazoxyfene [1,3-dimethyl-4-(2,4-dichlorobenzoyl)-Sphenacyloxy pyrazole] (200g), chlormethoxynil [2,4-dichlorophenyl-4-nitro-3-methoxyphenyl ether] (180g), dimepiperate [S-(1-methyl-1-phenethyl)-piperidine-l-carbathioate] (210g), dimepiperate + probenazol [3-allyloxy-1,2-benzisothiazol-1,1-dioxide] (210 + 120g) mixture and dimepiperate + probenazol + molinate [S-ethyl-N,N-hexamethylene-thiol-carbamate] (120 + 120 + 120g) mixture at times of application studied. Butachlor [2-chloro-2',6'-diethyl-N-buthoxymethyl acetanilide] + pyrazolate [4-(2,4-dichlorbenzoyl)-1,3dimethyl-pyrazol-5-yl-p-toluene-sulfonate] (70 + 120g) mixture and butachlor + chlormethoxynil (60 + 120g) mixture caused root length to shorten and root viability to decrease. However, the crop injury was recovered at 25 days after seeding. Benzophenap, pyraxoxyfene and butachlor + pyrazolate mixture were effective for weed control when applied at 2 days before seeding. Chlormethoxynil and butachlor + chlormethoxynil mixture was very effective for controlling annual weed. Dimepiperate, dimepiperate + probenazol mixture and dimepiperate + probenazol + molinate mixture did not control most weeds except for Echinochloa crus-galli (L.) Beauv.