• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.225-236
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• 2021

The epipyrone (EPN) biosynthetic gene cluster of Epicoccum nigrum is composed of epnC, epnB, and epnA, which encode cytochrome P450 oxidase, glycosyltransferase, and highly reducing polyketide synthase, respectively. Gene inactivation mutants for epnA, epnB, and epnC were previously generated, and it was found that all of them were incapable of producing EPN and any of its related compounds. It was also reported that epnB inactivation abolished epnA transcription, generating ΔepnAB. This study shows that the introduction of native epnC readily restored EPN production in ΔepnC, suggesting that epnC is essential for polyketide release from EpnA and implies that EpnC works during the polyketide chain assembly of EpnA. Introduction of epnC promoter-epnA restored EPN production in ΔepnA. The ΔepnB genotype was prepared by introducing the epnA expression vector into ΔepnAB, and it was found that the resulting recombinant strain did not produce any EPN-related compounds. A canonical epnB inactivation strain was also generated by deleting its 5'-end. At the deletion point, an Aspergllus nidulans gpdA promoter was inserted to ensure the transcription of epnA, which is located downstream of epnB. Examination of the metabolite profile of the resulting ΔepnB mutant via LC-mass spectrometry verified that no EPN-related compound was produced in this strain. This substantiates that C-glycosylation by EpnB is a prerequisite for the release of EpnA-tethered product. In conclusion, it is proposed that cytochrome P450 oxidase and glycosyltransferase work in concert with polyketide synthase to generate EPN without the occurrence of any free intermediates.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.503-507
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• 1999

To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methyl carba-moylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sedimnet. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1103-1108
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• 2002

In order to evaluate the degradation organophosphorus pesticide, EPN, in water environment, the effects of water temp.(10$^{circ}C,\;30^{\circ}C$), pH(3-11) and sunlight on its degradation were investigated during 10 days. The degradation rate of EPN(200 rpm) was faster at higher water temp. and higher pH, i.e., its degradation rate at pH 3, 5, 7, 9, 11 was 57, 63, 66, 69, 75%(1$0^{\circ}C$), and 70, 74, 79, 91, 97%(3$0^{\circ}C$) after 10 days, respectively. The effect of water temp. on its degradation was little in acidic condition, but was rather great in alkaline condition, with time. EPN was degraded fast at the alkaline condition by photolysis. At the condition of pH 11, EPN was degraded fast at the early stage in the first 2 days, but after that the degradation rate was weakened.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.19-25
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• 2000

The adsorption and leaching of organophosphorus pesticide, EPN (O-ethyl-O-4 -nitrophenyl phenyl phosphonothioate) were investigated in Namwon soil(black volcanic soil), Aewol soil(very dark brown volcanic soil) and Mureung soil(dark brown nonvolcanic soil) in Cheju Island. The residue of EPN was surveyed on coastal environment of Cheju in Aug. 1996. The organic matter of Namwon soil, Aewol soil and Mureung soil was 19.8, 6.2 and 2.4%, respectively. The cation exchange capacity of Namwon soil, Aewol soil and Mureung soil was 24.8, 13.0 and 9.5 meq/100 g, respectively. The Freundlich constant, k value, was 89.4, 26.9 and 9.25 for Namwon soil, Aewol soil and Mureung soil, respectively. The k value of Namwon soil with very high organic matter content and cation exchange capacity was the highest for Aewol soil and Mureung soil. The Freundlich constant, 1/n, show a high correlation with organic matter content, i.e. it is less than unity for organic matter rich soil of Namwon soil and greater than unity for organic matter poor soil of Mureung soil. The leaching of EPN was slower for Namwon soil with high k values, and faster for Mureung soil with low k values. The results of the study was demonstrated the potential of pollution for EPN have little leached into soil environment. EPN was not detected in seawater and sediment in the coastal environment in Cheju Island. EPN used in the farm on tile Cheju island were not residued in the coastal environment.

• Environmental Analysis Health and Toxicology
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• v.17 no.4
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• pp.341-346
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• 2002

To investigate the residue of organophosphorus pesticides such as Monocrotophos［Dimethyl-1-methyl-2-methyl carbamoylvinylphosphate］and EPN［O-ethyl-O-4-nitrophenyl phenylphosphonothioate］in the coastal environment of Cheju island, samples of sea organism, water and sediment were collected at the Sackdaldong and Daepodong near the Jungmoon golf course in July and Aug. 1997. The qualified detection limit of mono-crotophos and EPN by GC -FPD were 0.024 ng/g and 0.020 ng/g in the sea organism, respectively Neither Monocrotophos nor EPN was detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell (Batillus cornutus) and sea urchin (Anthocidaris Crassispina). They were not detected in seawater and sediment, either. These results showed that the coastal area near the Jungmoon golf course in the Cheju island was not polluted by the organophosphorus pesticides such as Monocrotophos and EPN.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.54-61
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• 2009

EPN-resistant diamondback moth were tested the developmental characteristics, longevity, fecundity and synergistic effect with synergists when treated with the bistrifluron, an inhibitor of chitin synthesis. Inhibition rate of egg hatch was below at the recommended concentration (50 ppm) to the EPN-resistant strain than EPN-non selected strain, however, mortality within 24hr after hatching was showed as 50-60%. They did not show the difference between two strains. Mortality of larval instars were showed effective to two strains with no difference. Inhibition rate of emergence did not show any effect when treated with pupae. Moreover, they did not affect to the longevity and fecundity. When bistrifluron was treated at 50 ppm to the adult, however, longevity and fecundity was decreased with no difference between two strains. Bistrifluron to the EPN-resistant strain showed synergistic effect as high as 137.7 and 73.1 folds with synergist such as PBO (microsomal oxidase inhibitor) and polyoxin B (chitin synthetase inhibitor), respectively.

• Analytical Science and Technology
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• v.18 no.3
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• pp.224-231
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• 2005

In this study, the optimum conditions for the LPME (liquid phase microextraction) were investigated to overcome several shortcomings of traditional liquid-liquid extraction method. The LPME, which is automatic and dynamic, was used to analyze the five pesticides (dementon-S-methyl, diazinon, parathion, fenitrothion, EPN) extracted from vegetable, and HP 6890 GC/NPD was used as an analytic instrument. It was possible to optimize the extraction condition using the automatic LPME. The optimum extraction rate was obtained at pH 3.0 and $100{\mu}g/mL$ of salt concentration and standard curve showed linearity with over $R^2=0.9921$ in the range of $0.2{\sim}10{\mu}g/g$. The relative standard deviations were 7.7%, 9.8%, 7.8%, 9.7% and 8.2% in the $5.0{\mu}g/g$ concentration of dementon-S-methyl, diazinon, parathion, fenitrothion and EPN, respectively. The acquired accuracies were satisfactory showing 12.7%, 7.8%, 10.4%, -6.7% and -0.7% for dementon-S-methyl, diazinon, parathion, fenitrothion and EPN respectively.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.1
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• pp.1-8
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• 2018

Purpose: Extremely hazardous pesticides are classified as World Health Organization (WHO) hazard class Ia. However, data describing the clinical course of WHO class Ia OP (organophosphate) poisonings in humans are very scarce. Here, we compare the clinical features of patients who ingested hazard class Ia OPs. Methods: This retrospective observational case study included 75 patients with a history of ingesting ethyl p-nitrophenol thio-benzene phosphonate (EPN), phosphamidon, or terbufos. The patients were divided according to the chemical formulation of the ingested OP. Data regarding mortality and the development of complications were collected and compared among groups. Results: There were no differences in the baseline characteristics and severity scores at presentation between the three groups. No fatalities were observed in the terbufos group. The fatality rates in the EPN and phosphamidon groups were 11.8% and 28.6%, respectively. Patients poisoned with EPN developed respiratory failure later than those poisoned with phosphamidon and also tended to require longer mechanical ventilatory support than phosphamidon patients. The main cause of death was pneumonia in the EPN group and hypotensive shock in the phosphamidon group. Death occurred later in the EPN group than in the phosphamidon group. Conclusion: Even though all three drugs are classified as WHO class Ia OPs (extremely hazardous pesticides), their clinical courses and the related causes of death in humans varied. Their treatment protocols and predicted outcomes should therefore also be different based on the chemical formulation of the OP.

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.153-159
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• 1990

Two fractions(microsomal and soluble) were prepared by ultracentrifugation(105,000G for 1hr at $4^{\circ}C$) from pig liver in order to find the major factor in Diazinon degradation. The two enzyme activities showed the same value, but Diazinon was degraded three times in microsomal fraction more than in soluble fraction. And with addition of EPN, Beam and PBO, degradation of diazinon was inhibited(29, 30 and 60%) as well as Monooxygenase activity (14, 15 and 35%) in microsomal fraction, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.4
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• pp.509-518
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• 1993

Protocol conversion is to resolve the imcompatibility between networks so that users on different protocols can communicate with each other. This paper designs a formal model, EPN , to increase its modeling power and analyze conversion protocol and proposes a conversion algorithm using it. The conversion algorithm has two capabilities : synchronization and automatic error recovery function. Therefore burden of protocol converter design will be reduced, automatic protocol converter design can be possible and implementation for half-gateway will be easy.