• Biomolecules & Therapeutics
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• v.15 no.3
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• pp.199-204
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• 2007

Carbamates have excellent insecticidal activities against a broad spectrum of insects. They possess knocking-down, fast-killing, and systemic effects, however, they are toxic to mammals. In this study, we have carried out in vitro genetic toxicity test of methylcarbamate and microarray analysis of differentially expressed genes in response to methylcarbamate. Methylcarbamate did not show mutations in base substitution strain TA1535 both with and without exogenous metabolic activation. Methylcarbamate did not show mutations in frame shift TA98 both with and without exogenous metabolic activation. Methylcarbamate showed DNA damage based on single cell gel/comet assay in L5178Y cells both with and without exogenous metabolic activation. Methylcarbamate did not increase micronuclei in CHO cells both with and without exogenous metabolic activation. Microarray analysis of gene expression profiles in L5178Y cells in response to methylcarbamate selected differentially expressed 132 genes that could be candidate biomarkers of genetic toxic action of methylcarbamate.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.170-177
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• 1989

In order to seek the molecular basis of higher insecticidal activity of the carbamates with two methyl groups, m-xylyl-N-methylcarbamate(MXNMC) than the corresponding unsubstituted phenyl N-methylcarbamate(PNMC), these two derivatives have been studied by molecular orbital(MO) theoretically using extended $H\ddot{u}ckel$ theory(EHT), and analysis of regression and linear free energy relationship(LFER). The most stable stereo structure(Z, Z) shows that the phenyl group occupies vertical(${\theta}=90^{\circ}$) position on the plane of the N-methylcarbamyl group. Regression analysis shows that especially good correlation exists between the $pI_{50}$ values and the calculated MO quantities when the hydrogen atomic charge of metaposition and of m-methyl groups, and LUMO energy are taken as variables. The LFER analysis on the carbamylation indicates that field(F) effect(60%) is slightly larger than resonance(R) effect(40%) in PNMC(E>R), whereas, in case of MXNMC, R effect(98.6%) is much larger than F effect(1.4%)($R{\gg}F$). From the basis on the findings, the enhancement of insecticidal activity of MXNMC may be the result of hyperconjugation by m-methyl groups.

• 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.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.124-130
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• 1985

Adsorption experiments of N-methylcarbamate insecticides on soils were carried out as a function of soil pH ana soil organic matter content with wet-and dry-land soils that were either oxidized or non-oxidized. The results obtained may be summarized as follows: The adsorption of N-methylcarbamate insecticides on soils was nearly leached to equilibrium after shaking for 12 hours. The adsorption of N-methylcarbamate insecticides was higher on sandy clay than sandy loam. The presence of organic matter in soil increased the adsorption of N-methrlcarbamate insecticides on soils. The mode of isothermal adsorption of N-methylcarbamate insecticides on soils was coincident with the Freundlich equation. Little effect of soil pH on the adsorption might be interpreted as that the adsorption was due to physical adsorption between N-methylcarbamate molecules and soil surface.

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.127-133
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• 1995

A Series of meta and para-substituted phenyl N-methylcarbamate derivatives were synthesized and influence of substituents(X) on the molecular orbital(MO) quantities of carbonyl group, carbamylation reaction center, and insecticidal activities($pI_50$) were discussed quantitatively. From these findings, the most stable streo conformer(Z) shows that the planer phenyl group occupies vertical(${\theta}=90^{\circ}$) position on the plane of the N-methylcarbamyl group. The carbamylation mechanism was proposed that the carbamylation process of acetylcholinesterase(ACh.E) by m-methyl substituted phenyl N-methylcarbamate derivatives proceeds via hyperconjugation of m-methyl group and carbonyl oxygene protonation, theromodynamically control reaction with acidic site of ACh.E.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.391-397
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• 2002

This study was carried out with the inhibition of the cholinesterase activity by carbamate insecticides in the chicken in vivo and in vitro. The optimum pH of cholinesterase was 8.0. The cholinesterase activity used the acetylcholin as substrate in plasma was 24.6 $\mu$mol/min/g protein. After oral administration with 0.32 mg/kg of BPMC as carbamate pesticide, the cholinesterase activity was inhibited to 60% of control after 15min in vivo. Then the recovery of cholinesterase activity followed to 97% of control after 12hr. I$_{50}$, such as concentration required for 50% inhibition of enzyme activity, of phenyl N-methylcarbamate were 329 $\mu\textrm{g}$/$\ell$ of XMC, 214 $\mu\textrm{g}$/$\ell$ of metolcarb, 111 $\mu\textrm{g}$/$\ell$ of BPMC, 107 $\mu\textrm{g}$/$\ell$ of propoxur and 104 $\mu\textrm{g}$/$\ell$ of isoprocarb. I$_{50}$ of aromatic N-methylcarbamate were 280 $\mu\textrm{g}$/$\ell$ of carbaryl and 114 $\mu\textrm{g}$/$\ell$ carbofuran.ran.

• 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.18 no.4
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• pp.255-258
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• 1974

The insecticidal activity of six lately synthesized carbamate derivatives of furfural oxime N-methylcarbamate (I), 5-methyljural oxime N-methylcarbamate (II), methyl p-(methylcarbamoyl) oxybenzoate (IV), ethyl p-(methylcarbamoyl) oxybenzoat(V), n-propyl p-(methyl carbamoyl)oxybenzoate(VI) and n-butyl p-(methyl carbamoyl)oxybenzoate examined using o.2w/v% acetone solutions of each compound. Among them, alkyl p-(methyl carbamoyl) oxybenzontes exerted slightly insecticidal effects on Sogata furcifera H$_{ORVATH}$, Delphacodes stria striatella FALLEN, wherease no significant effects were observed on Mil-aparvata Iugens Stal, Inazuma dorsolis Moischiulsky, and Naphotettix apicalis cincticeps U$_{HLER}$.

• Applied Biological Chemistry
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• v.21 no.1
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• pp.31-34
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• 1978

The stability of active ingredient of BPMC formulation under ultraviolet lights and sunlights was investigated using dust, emulsifiable concentrate and granular. The active ingredient of BPMC dust was more rapidly degraded by irradiation with ultraviolet lights than emulsifiable concentrate or granular tested. In the case of BPMC emulsions, the degree of degradation was increased in the order of granular, emulsifiable concentrate, dust by irradiation with ultraviolet lights. BPMC was unstable in alkaline solution and ultraviolet lights had highly significant relation to the decomposition of its active ingredient.

• Korean Journal of Environmental Agriculture
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• v.1 no.1
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• pp.14-21
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• 1982

Analytical methods for residues of six N-methylcarbamate insecticides were investigated to compare the minimum detectability, recovery from several crops and feasibility of multiple residue analysis. Those methods studied in this work included spectrophotometry by diazotization and gas chromatography by N-trifluoroacetylation(TFA), pentafluorobenzylether(PFB) and dinitrophenylether (DNP) derivatization. Maximum absorbed wavelength of the diazotized MIPC, XMC, BPMC, propoxur and carbofu ran was around 460 ㎚, while that of carbaryl recorded 510 ㎚. Recovery from brown rice and apple by diazotization method ranged from 80 to 120% and minimum detectable limits were 0.03 to 0.05 ppm in 50 g of the sample. Minimum detectability of PFB derivatives by gas chromatography was superior to TFA and DNP derivatives. DNP derivatives showed the longest retention time among the given derivatives. Recovery from crops by gas chromatographic met hod ranged 74 to 94%, 78 to 93%, and 85 to 99% in brown rice, rice straw and apple, respectively. Limit of detection was 0.01 ppm for TFA, 0.005 ppm for PFB and 0.02 ppm for DNP derivatives in 50 g of the crop samples.