• The Korean Journal of Pesticide Science
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• 제19권3호
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• pp.204-209
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• 2015

This study was carried out to investigate residual characteristics of insecticide acetamiprid in asparagus under greenhouse condition from July to August and consequentially to obtain basic data for guideline on safe use of this pesticide in asparagus. Residues of acetamiprid in young stem of asparagus before and after removing foliage were analyzed from samples harvested at 0, 1, 3, 5 and 7 days after single application before harvest. As a result, residues of acetamiprid in young stem of asparagus before and after removing foliage at 0 day were 0.27 mg/kg and 0.14 mg/kg, respectively, which were higher than tentative limit (0.1 mg/kg). However, 3 days later residues of acetamiprid were lower than the tentative limit, representing 0.08 mg/kg and 0.03 mg/kg in the asparagus before and after removing foliage, respectively. Acetamiprid was undetectable in both samples at 5 days since the concentrations were less than detection limit (0.02 mg/kg) in this study. In summary, the half-life of acetamiprid in asparagus regardless of removing foliage was quite short under greenhouse condition from July to August, in the range of 1-3 days, and single application of acetamiprid water dispersible granule in/on asparagus at 7 days before harvest would have no problem on safety issues about pesticide residue. This result might be basic information to construct guideline for safe use of acetamiprid in asparagus.

• Journal of Plant Biotechnology
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• 제41권3호
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• pp.146-158
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• 2014

Camelina sativa that belongs to Brassicaceae family is an emerging oilseed crop. Camelina seeds contain approximately 40% storage oils per seed dry weight, which are useful for human and animal diets and industrial applications. Microsomal delta-12 fatty acid desaturase2 (FAD2) catalyzes the conversion of oleic acid to linoleic acid. The polymorphisms of FAD2 genes are correlated with the levels of oleic acids in seed oils. Microsomal delta-12 fatty acid desaturase2 (FAD2) catalyzes the conversion of oleic acid to linoleic acid. The polymorphisms of FAD2 genes are correlated with the levels of oleic acids in seed oils. In this study, three CsFAD2 genes (CsFAD2-1, CsFAD2-2 and CsFAD2-3.1) were isolated from developing seeds of Camelina sativa (L.) cv. CAME. The nucleotide and deduced amino acid sequences of three CsFAD2 genes were compared with those from dicotyledon and monocotyledon plants including Camelina cultivars Sunesone and SRS933. Three histidine motifs (HECGH, HRRHH, and HVAHH) required for FAD activity and a hydrophobic valine or isoleucine residue, which is a SNP (single nucleotide polymorphism) marker related with enzyme activity are well conserved in three CsFAD2s. The expressions of CsFAD2-1 and CsFAD2-3.1 were ubiquitously detected in various Camelina organs, whereas the CsFAD2-2 transcripts were predominantly detected in flowers and developing seeds. The contents of oleic acids decreased, whereas the amounts of linoleic acid increased in dry seeds of transgenic fad2-2 lines expressing each CsFAD2 gene compared with fad2-2 mutant, indicating that three CsFAD2 genes are functionally active. The isolated CsFAD2 genes might be applicable in metabolic engineering of storage oils with high oleic acids in oilseed crops.

• Journal of Applied Biological Chemistry
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• 제57권3호
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• pp.235-242
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• 2014

The purpose of this study is the establishment of scientific processes for making food safety policies. Thus, we investigated pesticide residue level of the agricultural commodities from market, and performed risk assessment. Fifteen agricultural items are chosen based on the frequency of Korean consumption. The samples were collected from 9 cities where populations are more than one million. Total 283 active ingredients were monitoring ( total sample number =232). Single-analysis of target pesticides was for three kinds of possible growth regulators and the multicomponent analysis was for 280 kinds of pesticides, a total of 283 species were selected to perform the pesticide residues. Before monitoring the analytes, the improvements of the analytical methods were done by method validations under the CODEX analytical method development guidelines and can produce metrics that represent the international standards applied in accordance with the guidelines. In addition to residual pesticides detected during monitoring we compare the ADI to EDI values using detected result and dietary consumption data which is extracted from annual market basket survey. The 163 samples were non-detected in the total 232 samples so it means that every agricultural commodity will residual pesticides-free in 70.3%. The detected residual pesticides showed for a total of 69 cases (29.7%). Two of samples violate Korean MRL (0.9%). The ratio of EDI compared to ADI resulted in only from 0.00087 to 0.902%. In result, we can assume that all detected residual pesticides are very safe level and current policies of Korean pesticides control may be working.

• Journal of Food Hygiene and Safety
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• 제16권1호
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• pp.21-26
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• 2001

Risk assessment traditionally are conducted on individual chemicals; however, humans are exposed to multiple chemicals in daily life. The organophosphorus (OP) pesticides are considered in a single risk assessment because they act by a common mechanism of toxicity, and there is likely to be expose to multiple OP pesticides simultaneously or sequentially. The OP pesticides act by inhibiting the enzyme acetylcholinesterasc (AChE) and have available extensive database. AChE is widely distributed throughout the body, most importantly in the nervous system. Inhibition of AChE results in accumulation of acetylcholine in the nervous system that results in clinical signs of cholinergic toxicity, including increased salivation and lacrimation, nausea and vomiting, muscle fasciculation, lethargy and fatigue, among others. To conduct an exposure assessment for pesticides in the diet, we need to know the food consumption patterns of the populations, and the pesticide residue levels in the foods that are consumed. This study was conducted to identify cumulative dietary risk due to multiple OP pesticides that can be exposed through various foods. Total 22 food samples including cereals, vegetables and fruits were collected randomly two times from food markets in several sites (4 cities). The subjected foods were selected by regarding of highly consumed foods to general Korean people. The 12 OP pesticides including Acephate, Azinphos-methyl, Chlorpyrifos, and Diazinon were monitored. For the exposure assessment, general adult group of 60 kg body weight was regarded as target population and food consumption data suggested by Lee et al. (2000) were used as consumed value of individual food. Analyses of samples for OP pesticides have been carried out according to the multiclass multiresidue analysis method and acephate and methamidophos analysis method of Korea Food Code. In general the levels of OP pesticides found in the food samples were very low or not detected.

• Korean Journal of Microbiology
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• 제48권2호
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• pp.73-78
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• 2012

We previously reported that the truncated Cel44C-$Man26A_{P558}$ ${\beta}$-glycosyl hydrolase protein exhibits multifunctional activities, including cellulase, xylanase, and lichenase. DNA shuffling of the truncated Cel44C-$Man26A_{P558}$ enzyme was performed to enhance the enzymatic activity of the multifunctional ${\beta}$-glycosyl hydrolase. Two mutant enzymes, M2Cel44C-$Man26A_{P558}$ that carries one mutation (P438A) and M21Cel44C-$Man26A_{P558}$ that carries two mutations (A273T and P438A) were obtained. The enzymatic activity of the M21Cel44C-$Man26A_{P558}$ double mutant was lower than enzymatic activity of the single mutant (M2Cel44C-$Man26A_{P558}$). However, both mutants displayed the enhancements in their enzyme activities that were ${\approx}1.3$- to 2.2-fold higher than the original enzymatic activity in Cel44C-$Man26A_{P558}$. In particular, the mutant M2Cel44C-$Man26A_{P558}$ exhibited an approximate 1.5- to 2.2-fold increase in the cellulase, xylanase, and lichenase activities in comparison with the control (Cel44C-$Man26A_{P558}$). The optimum cellulase, linchenase, and xylanase activities of ${\beta}$-glycosyl hydrolase were observed at pH 7.0, pH 7.0 and pH 6.0, respectively. These results, therefore, suggest that the amino acid residue Ala438 plays important roles in the enhancement of the activity of multifunctional ${\beta}$-glycosyl hydrolase.

• Analytical Science and Technology
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• 제25권4호
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• pp.257-264
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• 2012

Penicillins belong to the ${\beta}$-lactam class of antibiotics, and are frequently used in human and veterinary medicine. Despite the positive effects of these drugs, improper use of penicillins poses a potential health risk to consumers. This study has been undertaken to determinate multi-residues of penicillins, including amoxicillin, ampicillin, oxacillin, bezylpenicillin, cloxacillin, dicloxacillin, and nafcillin, using liquid chromatographic tandem mass spectrometer (LC-MS/MS). The developed method was validated for specificity, precision, recovery, and linearity in livestock and marine products. The analytes were extracted with 80% acetonitrile and clean-up by a single reversed-phase solid-phase extraction step. Six penicillins presented recoveries higher than 76% with the exception of Amoxicillin. Relative standard deviations (RSDs) were not more than 10%. The method was applied to 225 real samples. Benzylpenicillin was detected in 12 livestock products and 7 marine products. Amoxicillin, ampicillin, cloxacilllin, dicloxacillin, nafcillin and oxacillin were not detected. The detected levels were 0.001~0.009 mg/kg in livestock products excluding eggs and milk. In marine products, the detected levels were under 0.03 mg/kg. They were under the MRL levels. As monitoring results, it is identified to be safe but it is considered that safety management of antibiotics should continue by monitoring.