• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.578-581
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• 1989

Two enantiomers of various 2-hydroxy acid esters have been resolved as the 3,5-dinitrophenyl carbamates on chiral stationary phases (CSPs) derived from ${\alpha}-arylalkylamines.$ Two CSPs, each of which contains the same type of chiral moiety, but shows different mode of connection to a silica support, have been found to show the contrasting resolution behaviors. From the contrasting resolution behaviours of two CSPs used in this study, two competing chiral recognition mechanisms are proposed.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.128-134
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• 2001

Single cell gel electrophoresis (SCGE) assay, also called comet assay, is a rapid and sensitive method to detect DNA damage in single cell level. To evaluate the DNA damage of lymphocytes of pesticides sprayers, SCGE assay was carried out for 50 pesticides sprayer and 58 control subjects. They were interviewed with structured questionnaire to get the information about the kinds and amount of pesticide. Insecticides and fungicides were predominant among pesticides. Major components of pesticides were organophosphorus, organosulfate, cartap, carbamates, and triazole. Sprayed pesticides were classified into two groups. Group I included organophosphorus, organoarsenic, organotin, tetrazine, triazole and gramoxone, which were known to cause DNA damages. Group II pesticide were carbamates, surfactants, organosulfates, etc., which were not found as DNA damaging agents in scientific documents. Olive tail moments of 100 lymphocytes were measured by KOMET 3.1 program for each person. The means of tail moments were compared between farmers exposed to pesticides and control subjects. Farmers showed higher tail moments than control subjects (2.07$\pm$1.40 vs 1.53$\pm$0.77, p<0.05). The means of tail moments also were compared among group I sprayers (n=36), group II sprayers (n=24) and, control subject, and the means or tail moments were 3.4s$\pm$3.2o, 2.66$\pm$2.20 and 1.53$\pm$0.77 respectively. The difference between means of group I sprayers and controls was statistically significant (p<0.05). In conclusion, this study showed higher DNA damage in farmers exposed to pesticides than control subjects, and comet assay could be useful as a biological monitoring method of genotoxic pesticides for farmers.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.75-82
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• 1994

Bioconcentration Factor (BCF) is known as important criteria for ecotoxicology on hazardous chemicals. But there is no standard method for determining BCF and reported BCFs were slightly different in accordance with authors. This study was performed with aims to determine BCFs on BPMC and Carbaryl. Carassius auratus(goldfish) be chosen as test organism and test period were 3-day, 5-day and 10-day. Extract solvents were n-hexane and acetonitrile. GC-ECD was used to detecting carbamates. The obtained results were as follows: 1. It was possible to determine short term BCF$_s$ of Carbaryl or BPMC through relatively simple procedure. 2. BCF$_3$ of Carbaryl in concentration of 1, 2, 5, 10 ppm were 0.34 $\pm$ 0.06, 0.18 $\pm$ 0.02, 0.10 $\pm$ 0.01, 0.06 $\pm$ 0.01 respectively. BCF$_5$ of Carbaryl were 0.34 $\pm$ 0.05, 0.18 $\pm$ 0.02, 0.13 $\pm$ 0.01 and 0.07 $\pm$ 0.01, BCF$_{10}3$ of Carbaryl were 0.45 $\pm$ 0.05, 0.27 $\pm$ 0.02, 0.16 $\pm$ 0.02 and 0.09 $\pm$ 0.01. BCF$_3$ of BPMC in concentration of 1, 2, 5 ppm were 4.66 $\pm$ 0.17, 2.64 $\pm$ 0.49, 1.88 $\pm$ 0.24 respectively. BCF$_5$ of BPMC were 4.09 $\pm$ 0.50, 2.42 $\pm$ 0.37 and 1.83 $\pm$ 0.15. 3. BCF$_s$ of BPMC were decreased as increasing concentration. However, BPMC concentration in fish were increased in contrast to BCF. But more concentrated BPMC was found in fish 3-day test than found concentration in fish 5-day test. 4. Same trend appeared in Carbaryl. BCF$_s$ of Carbaryl were decreased as increasing concentration and prolonging test period. But found Carbaryl concentration in fish were increased. 5. BCF$_s$ of BPMC were higher than that of Carbaryl by 10 times, in spite of the physicochemical properties of the two carbamates were similar to each other. Further study is recommended to find out the reason of the difference.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.154-161
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• 1989

1,3-Dimethyl-4-acyl-5-hydroxypyrazoles were treated with methyl isocyanate to give corresponding carbamates. They were 1,3-dimethyl-4-benzoyl-pyrazol-5-yl N-methylcarbamate(V), 1, 3-dimethyl-4-(2-chlorobenzoyl)-pyrazol-5-y1 N-methyl-carbamate(VI), and 1, 3-dimethyl-4-(2,4-dichlorobenzoy1)-pyrazol-5-yl N-methyl-carbamate(VII). The structures of the compounds were fully identified by UV, IR, $^{1}H-NMR$ and $^{13}C-NMR$. The synthesized carbamate compounds were tested for the phytotoxicity on the seed germination and the seedling growth of rice, radish, green-pea and turf grass. At 50ppm concentraction, the germination of seeds was not significantly affected. At higher concentraction, however, phytotoxic tendency on the seed germination and seedling growth was observed. In addition, these compounds were less phytotoxic to rice and turf seedlings as compared with radish and green pea seedlings.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.75-81
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• 2010

The reaction of N,N-diethyl carbamates of 1H-[1,2,3]triazolo[4,5-b]pyridin-1-ol (4-HOAt) 7, 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol (7-HOAt) 8, 1H-benzo[d][1,2,3]triazol-1-ol (HOBt) 9, 6-chloro-1H-benzo[d][1,2,3]triazol-1-ol (Cl-HOBt) 10, 6-(trifluoromethyl)-1H-benzo[d][1,2,3]triazol-1-ol ($CF_3$-HOBt) 11, and 6-nitro-1H-benzo[d][1,2,3]triazol-1-ol ($NO_2$-HOBt) 12 with morpholine and piperidine in $CH_3CN$ underwent acyl nucleophilic substitution to give the corresponding carboxamide derivatives. The reactants and products were identified by elemental analysis, IR and NMR. We measured the kinetics of these reactions spectrophotometrically in $CH_3CN$ at a range of temperatures. The rates of morpholinolysis and piperidinolysis were found to fit the Hammett equation and correlated with $\sigma$-Hammett values. The values were 1.44 - 1.21 for morpholinolysis and 1.95 - 1.72 for piperidinolysis depending on the temperature. The $Br{\phi}$nsted-type plot was linear with a $\beta_lg = -0.49 \pm 0.02$ and $-0.67 \pm 0.03$. The kinetic data and structure-reactivity relationships indicate that the reaction of 9-12 with amines proceeds by a concerted mechanism. The deviation from linearity of the correlation ${\Delta}H^#$ vs. ${\Delta}S^#$ and plot of $logk_{pip}$ vs. $logk_{morph}$ and $Br{\phi}$nsted-type correlation indicate that the reactions of amines with carbamates 7 and 8 is attributed to the electronic nature of their leaving groups.

• Journal of the Korean Chemical Society
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• v.36 no.3
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• pp.366-375
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• 1992

The aminolysis of carbamates are studied MO theoretically using AM1 method. The results indicated that the reactivity is determined by bond-making and-breaking and steric effects; as a result the $B_{AC}2$ mechanism is favored due to favorable contribution of bond formation in agreement with experimental results. We found that although thermal 2＋2 reaction is forbidden, it becomes allowed when the total electrons involved are six in a four-center reaction and proceeds by a consecutive onestep mechanism. Comparison of activation barriers show that greater energy is required in breaking a sigma bond compared with the energy required for breaking a $\pi$ bond, by 17 kcal/mol and the six membered ring structure is favored about 5 kcal/mol sterically.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.19-24
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• 1996

Carbamates are generally used as insecticide, thus 5.7-dichloro-8~hydroxyquinolinyl- N-ethylcarbamate was newly synthesized. Its physical properties were determined and chemical structure was identified by means of I.R., nmr in addition to elemental analysis. The yield of addition, using triethylamine as catalyst, 5.7-dichloro-8-hydroxyquinoline and isocyanate was better than that of condensation of 5.7-dichloro-8-hydroxyquinoline with carbamoylchloride. The effct of the compound on rabbit's ileum, and antibacterial activity against Staphylococcus aureus, Salmonella typhi, Echerichia coli, and Pseudomonas aeruginosa were examined. The present organic synthesized compound showed the bacteriostatic action on salmonella typhi, escherichia coli, and pseudomonas aeruginosa, but no otherwise effect of contraction of rabbit's ileum in the concentration of $250 \mu g/ml$.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.62-65
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• 1997

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(5,7-dibromo-8-hydroxyquinolinyl-N-methylcarbamate(I), 5,7-dibromo-8-hydroxyquinolinyl-N-ethylcarbamate(II)) was examined using 0.2w/v% acetone solutions and 50 $\mu$g/ml-1000 $\mu$g/ml N,N'-dimethylformamide H$_2$O(2:3) solutions of each compounds, respectively. 1. Two carbamates exerted insectiddal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN and Nilaparvate lugens STAL, Whereas no significant effects were observed on the Inazuma dorasalis MOISCHIULSKY Nephateffix apicalis Cincticeps UHLER. 2. These compounds exhibited growth-inhibitory activity against Staphyloccus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401, at the concentration range of 100-500 $\mu$g/ml in general.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.739-745
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• 2001

Of all pesticides, carbamates are known to be most common, since alternatives such as organophosphates have long lifetime and are extremely toxic to produce a delayed neurotoxic effect. Although a number of studies about toxicity of carbofuran, a most widely used carbamate, have been reported, its cardiovascular toxicity has not yet been studied. In the present study, we investigated its cardiovascular toxic effect in anesthetized rat in vivo and in isolated Langendorff rat heart, In anesthetized rat model, carbofuran (10 mg/kg) significantly reduced heart rate, and transiently increased blood pressure. In isolated rat heart, carbofuran (10${\mu}{\textrm}{m}$) caused a significant depression in the left ventricular developed pressure (LVDP), indicating contractile dysfunction by carbofuran. Carbofuran (10${\mu}{\textrm}{m}$) also decreased coronary flow rate (CFR) in isolated heart, indicating carbofuran-induced coronary dysfunction. These results suggest that carbofuran can cause cardiac dysfunction in rat in vivo and vitro.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.382-390
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• 2005

chial allylic ethers with a hydroxyl group attached to the $\pi-system$ and chlorosulfonyl isocyanate. The enantioselectivity of the CSI reaction with the chiral allylic and benzylic ethers was examined in various solvents and temperatures. Based on these results, it was proposed that the CSI reaction is a competitive reaction of a $S_{N}i$ (retention) and a $S_{N}1$ mechanism (racemization) according to the stability of the carbocation intermediate. This means that there is a greater proportion of retention with the less stable the carbocation intermediate and vise versa.