• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.171-181
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• 2012

Lysine is the first limiting essential amino acid in cereals for humans and monogastric animals, although its content is generally low. A chemically induced high-lysine barley mutant, M98, has an agronomically undesirable shrunken endosperm trait. In order to obtain detailed insight into the atypical traits of M98 grains, we characterized amino acid composition and protein profiles of M98 and its parent cultivar Chalssalbori. Among a total of 16 amino acids, the percentage of each of the 7 amino acids, including lysine, was 1.2~1.8 times higher in M98, comparing to Chalssalbori. The percentage of proline and its precursor, glutamic acid, in M98 was about the half of that of the amino acids in Chalssalbori, but arginine synthesized from glutamic acid was 1.8 times higher in M98, compared that in the parent cultivar. Theses results indicated that the mutation in M98 grains might alter the proportion of amino acids linked to each other in a biosynthetic pathway. A comparison of grain proteome profiles between Chalssalbori and M98 revealed 70 differentially expressed protein spots, where 45 protein spots were up-regulated and 25 protein spots down-regulated in M98 compared to those in Chalssalbori. Of these changed protein spots, 53 were identified using nano-electrospray ionization liquid chromatography mass spectrometry. Most of these identified proteins were involved in various biological processes. In particular, 28 protein spots such as ${\beta}$-amylase, serpins and B3-hordein were identified as proteins associated with the atypical traits of M98. It was thought that a genetic study on the unique protein profile of M98 would be needed to develop an agronomically feasible barley cultivar with high-lysine trait.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.270-277
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• 2016

BACKGROUND: Significant amount of bisphenol A has been released from the manufacturing process of plastics, epoxy resins, dental material and flame retardants. Bisphenol A has been detected at trace levels in wastewater, surface water, landfill leachate and drinking water. However, the residual survey of bisphenol A has not been performed in agricultural reservoir beside agricultural environment cultivating crops. This study was conducted to monitor the residual bisphenol A in national agricultural reservoirs and understand a level of contamination of bisphenol A in the agricultural environment in Korea. METHODS AND RESULTS: The water and water sediment were collected at agricultural reservoirs in Chungnam, Chungbuk, Kyunggi, Jeonnam, Jeonbuk, Kyungnam and Kyungbuk province. Bisphenol A was analyzed by the LC-MS/MS with triple quad 4500. The recovery of water and water sediment in the agricultural reservoirs showed the level of 95.7~97.2% and 91.5~100.3%, respectively. CONCLUSION: Bisphenol A was detected at the level of $0.05{\mu}g/L{\sim}0.18{\mu}g/L$ and $0.1{\mu}g/kg{\sim}34{\mu}g/kg$ in water and water sediment of the reservoirs, respectively. Based on the results, the residue of bisphenol A will be tried in the crops surrounding these agricultural reservoirs where bisphenol A detected above $10{\mu}g/kg$ of bisphenol A.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.279-287
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• 2017

BACKGROUND: Many farmers who cultivate the strawberries for export have used agricultural chemicals which MRL (Maximum Residue Limits) of main export target countries or simultaneous multi-residue analysis in Korea have not been established. Among them, the cyenopyrafen and cyflumetofen were selected and applied to this study to determine the PHI (pre-harvest interval) which is appropriate to the PLS (Positive List System) criterion (0.01 mg/kg) and to investigate the residual amounts in the samples. In addition, Fifty pesticides were monitored to check up whether it is suitable or not for main export target countries. METHODS AND RESULTS: Cyenopyrafen and cyflumetofen were spayed out to the strawberries. Samples for residual analyses were taken for maximum 60 days. After sampling, they were extracted by the QuEChERS method and analyzed using the LC-MS/MS. Cyenopyrafen and cyflumetofen were detected in a range of 0.0106~2.6517 mg/kg and of 0.0005~1.4480 mg/kg, respectively. From this results, they were found to be suitable for PLS concentration after 30 or 45 days after spray. In addition, they were detected in most samples that were selected at random. Their concentrations were higher than the PLS criterion in the maximum twenty samples. Twelve of pesticides unsuitable for main export target countries have been detected in the monitoring of simultaneous multi-residue analysis. The result indicates they are unsuitable for export since they excesses over PLS criterion. CONCLUSION: The monitoring result showed it is necessary to establish the pesticide standards of safe use suitable for the PLS criterion. In addition, it is considered continues management and inspection are needed to solve problems caused by unsuitable pesticides in export strawberries.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.250-260
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• 2012

In the present study, the antioxidative and antibacterial activities of Artemisia princeps Pampanini (A. princeps Pamp.) extract were investigated. The ethyl acetate fraction of A. princeps Pamp. showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}=12.27{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of A. princeps Pamp. extract on $Fe^{3+}-EDTA/H_2O_2$ systems were investigated using a luminol-dependent chemiluminescence assay. The ethyl acetate fraction of the extract ($OSC_{50}=0.33{\mu}g/mL$) had a 5 times greater ROS scavenging activity than L-ascorbic acid ($1.50{\mu}g/mL$), known as a water soluble antioxidant. The cellular protective effects of fractions of A. princeps Pamp. on the rose-bengal sensitized photohemolysis of human erythrocytes were examined. The aglycone fraction of extracts suppressed photohemolysis in a concentration dependent manner. The inhibitory effects of A. princeps Pamp. extract on tyrosinase were investigated to assess their whitening efficiency. The ethyl acetate fraction demonstrated a 7 times higher tyrosinase inhibitory effect ($IC_{50}=29.20{\mu}g/mL$) than albutin, known as a whitening agent. The antibacterial activity of ethyl acetate fractions against various normal skin flora were measured. The results showed that the antibacterial activity of the fraction was the highest on Staphylococcus aureus, Bacillus subtilis, and Propionibacterium acnes. Antioxidant substances were isolated and purified from the ethyl acetate fractions. Eupatilin and jaceosidin were identified. These results indicate that the extract/fractions of A. princeps Pamp. can function as antioxidant and/or antibacterial agents for the skin.

• Analytical Science and Technology
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• v.35 no.3
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• pp.136-142
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• 2022

According to media reports, the carcasses of euthanized abandoned dogs were processed at high temperature and pressure to make powder, and then used as feed materials (meat and bone meal), raising the possibility of residuals in the feed of the anesthetic ketamine and dexmedetomidine used for euthanasia. Therefore, a simultaneous analysis method using QuEChERS combined with high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was developed for rapid residue analysis. The method developed in this study exhibited linearity of 0.999 and higher. Selectivity was evaluated by analyzing blank and spiked samples at the limit of quantification. The MRM chromatograms of blank samples were compared with those of spiked samples with the analyte, and there were no interferences at the respective retention times of ketamine and dexmedetomidine. The detection and quantitation limits of the instrument were 0.6 ㎍/L and 2 ㎍/L, respectively. The limit of quantitation for the method was 10 ㎍/kg. The results of the recovery test on meat and bone meal, meat meal, and pet food showed ketamine in the range of 80.48-98.63 % with less than 5.00 % RSD, and dexmedetomidine in the range of 72.75-93.00 % with less than 4.83 % RSD. As a result of collecting and analyzing six feeds, such as meat and bone meal, prepared at the time the raw material was distributed, 10.8 ㎍/kg of ketamine was detected in one sample of meat and bone meal, while dexmedetomidine was found to have a concentration below the limit of quantitation. It was confirmed that the detected sample was distributed before the safety issue was known, and thereafter, all the meat and bone meal made with the carcasses of euthanized abandoned dogs was recalled and completely discarded. To ensure the safety of the meat and bone meal, 32 samples of the meat and bone meal as well as compound feed were collected, and additional residue investigations were conducted for ketamine and dexmedetomidine. As a result of the analysis, no component was detected. However, through this investigation, it was confirmed that some animal drugs, such as anesthetics, can remain without decomposition even at high temperature and pressure; therefore, there is a need for further investigation of other potentially hazardous substances not controlled in the feed.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.107-121
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• 2023

This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC₅₀ = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.241-246
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• 2007

Purpose: $[^{11}C]6-OH-BTA-1$ ([N-methyl-$^{11}C$]2-(4'-methylaminophenyl)-6-hydroxybenzothiazole, 1), a -amyloid imaging agent for the diagnosis of Alzheimer's disease in PET, can be labeled with higher yield by a simple loop method. During the synthesis of $[^{11}C]1$, we found the formation of by-products in various solvents, e.g., methylethylketone (MEK), cyclohexanone (CHO), diethylketone (DEK), and dimethylformamide (DMF). Materials and Methods: In Automated radiosynthesis module, 1 mg of 4-aminophenyl-6-hydroxybenzothiazole (4) in 100 l of each solvent was reacted with $[^{11}C]methyl$ triflate in HPLC loop at room temperature (RT). The reaction mixture was separated by semi-preparative HPLC. Aliquots eluted at 14.4, 16.3 and 17.6 min were collected and analyzed by analytical HPLC and LC/MS spectrometer. Results: The labeling efficiencies of $[^{11}C]1$ were $86.0{\pm}5.5%$, $59.7{\pm}2.4%$, $29.9{\pm}1.8%$, and $7.6{\pm}0.5%$ in MEK, CHO, DEK and DMF, respectively. The LC/MS spectra of three products eluted at 14.4, 16.3 and 17.6 mins showed m/z peaks at 257.3 (M+1), 257.3 (M+1) and 271.3 (M+1), respectively, indicating their structures as 1, 2-(4'-aminophenyl)-6-methoxybenzothiazole (2) and by-product (3), respectively. Ratios of labeling efficiencies for the three products $([^{11}C]1:[^{11}C]2:[^{11}C]3)$ were $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ in MEK, $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$ in CHO, $9.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$ in DEK and $7.6{\pm}0.5%:0.0%:0.0%$ in DMF, respectively. Conclusion: The labeling efficiency of $[^{11}C]1$ was the highest when MEK was used as a reaction solvent. As results of mass spectrometry, 1 and 2 were conformed. 3 was presumed.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.173-184
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• 2019

BACKGROUND: This study was carried out to investigate pesticide residues from fifty streams in Korea. Water samples were collected at two times. Thee first sampling was performed from april to may, which was the season for start of pesticide application and the second sampling event was from august to september, which was a period for spraying pesticides multiple times. METHODS AND RESULTS: The 136 pesticide residues were analyzed by LC-MS/MS and GC/ECD. As a result, eleven of the pesticide residues were detected at the first sampling. Twenty eight of the pesticide residues were detected at the second sampling. Seven pesticides were frequently detected from more than 10 water samples. Ecological risk assessment (ERA) was carried out by using residual and toxicological data. Four scenarios were applied for the ERA. Scenario 1 and 2 were performed using LC50 values and mean and maximum concentrations. Scenarios 3 and 4 were conducted by NOEC values and mean and maximum concentrations. CONCLUSION: Frequently detected pesticide residues tended to coincide with the period of preventing pathogen and pest at paddy rice. As a result of ERA, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole, and oxadiazon) were assessed to be risks at scenario 4. However, only oxadiazon was assessed to be a risk at scenario 3 for the first sampling. Oxadiazon was not assessed to be a risk at the second sampling. It seems to be temporary phenomenon at the first sampling, because usage of herbicides such as oxadiazon increased from April to march for preventing weeds at paddy fields. However, this study suggested that five pesticides which were assessed to be risks need to be monitored continuously for the residues.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.375-381
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• 2007

Deoxynivalenol (DON) and zearalenone (ZEN) are naturally occurring toxins produced by Fusarium species, which may grow on cereals. The aims of this study were to determine the incidence and contamination levels of DON and ZEN in cereal products. Seventy samples of cereal products were randomly selected from retail outlets during 2005 and 2006. DON and ZEN were analyzed by using high performance liquid chromatography with fluorescence and UV-detector, respectively. Detection limits were $4.4{\mu}g\;kg^{-1}$ for DON and $3.4{\mu}g\;kg^{-1}$ for ZEN. DON and ZEN were detected in 37 and 17, respectively, of the 70 samples, but the levels found were very low. In particular, out of 70 samples, 12 samples of corn and barley were co-contaminated with DON and ZEN, with levels ranging from 5.6 to $1842.3{\mu}g\;kg^{-1}$ for DON and 12.1 to $174.9{\mu}g\;kg^{-1}$ for ZEN, respectively. However, DON and ZEN were not detected in breakfast cereals and wheat flour. The highest level was found in dried corn kernel samples that confirmed by LC-MS. This study show that DON and ZEN co-contaminate with low levels in cereal products.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.553-557
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• 2011

Garlic specific organic compounds were separated and purified using a recycling preparative high-performance liquid chromatography (HPLC) from blanched garlic cloves. Identification of the compounds involved comparing the previously reported HPLC retention times as well as other identification methods including $^1H$- and $^{13}C$-nuclear magnetic resonance and liquid chromatography-mass spectrometry. The yields of garlic specific organic compounds were 12.2, 42.5, 1.6, 1.2, and 4.8% on wet weight basis of garlic for alliin(S-allyl-L-cysteine sulfoxide), isoalliin(S-1-propenyl-L-cysteine sulfoxide), ${\gamma}$-glutamyl-S-allylcysteine, ${\gamma}$-glutamyl-S-1-propenylcysteine and ${\gamma}$-glutamyl-phenylalanine, respectively. All the compounds, except for ${\gamma}$-glutamylphenylalanine, contained sulfur.