Il Kyu Cho - Academia.edu (original) (raw)

Papers by Il Kyu Cho

Korean Journal of Environmental Agriculture, 2021

BACKGROUND: The concern over heavy metal(loid)s in arable land and agricultural products increase... more BACKGROUND: The concern over heavy metal(loid)s in arable land and agricultural products increases for public health in recent years. This study aims to identify transition characteristics of heavy metal(loid)s and to assess dietary risk in barley grown at the major producing districts in Korea. METHODS AND RESULTS: The soil and barley samples were collected from 38 locations around the major producing districts at Jeollabuk-do in Korea for the propose of examining the concentrations of heavy metal(loid)s. The 34 barley samples were separately purchased on the market for the same survey. The average concentration and range of arsenic (As), cadmium (Cd) and lead (Pb) in barley grown at the major producing districts in Korea were 0.

Korean Journal of Environmental Agriculture

BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit... more BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study was carried out to propose import tolerance using OECD maximum residue limit (MRL) calculator for the export promotion of kiwifruit to Taiwan. METHODS AND RESULTS: The thiamethoxam residue in kiwifruit was determined by using the LC-TriQ-MS/ MS with the analytical process to set up the import tolerance under greenhouse conditions for Taiwan. Excellent linearity was observed for all of the analytes with a determination coefficient (R 2)≥0.99. The limit of quantification was determined to be 0.01 mg/kg for both thiame

Biomedical Chromatography, 2021

For export promotion, import tolerance of thiacloprid in strawberry was proposed using OECD Maxim... more For export promotion, import tolerance of thiacloprid in strawberry was proposed using OECD Maximum Residue Limit (MRL) calculator after conducting three different field trials. Pre-harvest interval (PHI) of residual pattern and degradation dynamic of thiacloprid in strawberry were determined using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Samples were extracted with acetonitrile and a mixture of salts and dilution was performed for purification. A six point matrix matched calibration curve was constructed which provided excellent linearity with coefficient of determination (R2 ) ≥ 0.9998. Detection and quantification limits were 0.003 mg/kg and 0.01 mg/kg respectively. The method was validated in quintuplicate at three different concentrations resulted acceptable recovery ranging from 80.86~101.71% with relative standard deviation (RSD) ≤ 6.50 among the three filed sites. The developed method was applied to the field treated sample harvested at different intervals. In PHI trial, the thiacloprid residues were ranged 0.24~0.70 mg/kg in the field site 1 (Nonsan), 0.16 ~ 0.50 mg/kg in the field site 2 (Sunchang), and 0.36 ~ 0.50 mg/kg in the field site 3 (Sacheon). Whereas, in the degradation trial, the observed residues were 0.03 ~ 0.81 mg/kg in the field site 1, and 0.02 ~ 0.48 mg/kg in the field site 2. Consequently, the import tolerance of thiacloprid in strawberry using OECD MRL calculator was proposed to 2 mg/kg, which is exactly same as the MRL established by Republic of Korea. In conclusion, the residue study supported to propose 2.0 mg/kg as a MRL of thiacloprid for strawberry..

Korean Journal of Environmental Agriculture, 2021

BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticide... more BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticides against fungal diseases in the world. However, benomyl is rapidly hydrolyzed in the environment after using to control plant diseases and has adverse effects by generating carbendazim, which is toxic to plants, humans, and the environment. METHODS AND RESULTS: In this study, the decomposition effect of carbendazim, a degradation product of benomyl was conducted in pot and field after making a prototype of benomyl-degrading microbial agent (BDMA). We found that the carbendazim-degrading microbial agent (CDMA) (10 5 , 10 6 , and 10 7 cfu/g soil) decomposed carbendazim by 50% or more in all the treatments, compared to the untreated control in the pot tests after four weeks. The effect of 100% decomposition of carbendazim was observed at 7 days after treatment, when the prototype of BDMA was apllied at 10-folds dilution in the field. The decomposition effect at more than 60% and plant growth promoting effect were observed after 7 days of the treatment, compared with the untreated group in the second field experiment,treated with commercially available concentrations of 500-folds and 1,000-folds. CONCLUSION(S): These results might represent that the BDMA would decompose carbendazim effectively, a de

Journal of proteomics & bioinformatics

Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of protein... more Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of proteins and has shown a high potential for bacterial identification and characterization. Type strains of four species of rhizobia and Escherichia coli DH5α were employed as reference bacteria to optimize various parameters for identification and classification of species of rhizobia by matrix-assisted laser desorption/ionization time-of-flight MS (MALDI TOF MS). The parameters optimized included culture medium states (liquid or solid), bacterial growth phases, colony storage temperature and duration, and protein data processing to enhance the bacterial identification resolution, accuracy and reliability. The medium state had little effects on the mass spectra of protein profiles. A suitable sampling time was between the exponential phase and the stationary phase. Consistent protein mass spectral profiles were observed for E. coli colonies pre-grown for 14 days and rhizobia for 21 days at 4°C ...

Korean Journal of Environmental Agriculture

BACKGROUND: Diquat dibromide is a fast-acting nonselective herbicide and plant growth regulator. ... more BACKGROUND: Diquat dibromide is a fast-acting nonselective herbicide and plant growth regulator. In this study, in order to understand the possibility of unintentional pesticide contamination in the following crops, the phytotoxicity and transition of diquat dibromide residue in soil into the following crops such as pepper, radish, lettuce and corn have been assessed through phytotoxicity trial and residual evaluation in the unintentional contamination of the higher residual diquat dibromide. METHODS AND RESULTS: The pepper, radish, lettuce and corn were cultivated in the sandy soil and loam soil where the 35 mg/kg and 90 mg/kg diquat dibromide were applied, respectively. Mild growth inhibition symptoms were observed in radish, lettuce and corn crops at the 90 mg/kg-diquat dibromide treatment on the 30 day of cultivation. Diquat dibromide was analyzed using liquid chromatography QTRAP (LC-MS/MS). The recovery rates of diquat dibromide from soil and crop were determined within range from 89.1 to 116.4% with relative standard deviation less than 14.7%. Diquat dibromide residues in soil were found to be 23.90-30.22 and 69.59-82.57 mg/kg from the 35 mg/kg and 90 mg/kg of diquat dibromide-treated soil, respectively after 30 days of crop cultivation. This result implicates that diquat dibromide did not convert to metabolites and remained mostly in the soil, even though it was partially decomposed during crop cultivation. In addition, the diquat dibromide in pepper and radish that were grown for 47 days, and lettuce and corn that were cultivated for 30 days were detected to be

Korean Journal of Applied Entomology, 2020

GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It i... more GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It is effective and selective against harmful algal blooms (HABs). HABs cause serious problems for public health and fishery industries. Algae that cause HABs include Microcystis spp., Anabaena spp., and Aphanizomenon spp. Blooms of toxin-producing Microcystis aeruginosa occur regularly in fresh water where is rich in nitrogen and phosphorus nutrients. Environmental fate studies are needed to investigate the degradation of GreenTD. In the present study, we studied the persistence of GreenTD (90% aqueous solution) in water and toxic effects GreenTD on M. aeruginosa and reduction of microcystin production in the culture media. GreenTD was added in the water pots and microcystis media tubes at levels of 25 g/0.1 ha (0.5 mg/kg) and 50 g/0.1 ha (1.0 mg/kg). Samples were collected after 1, 3, 5, 7 and 14 days. The residues of GreenTD and microcystins in water and the media were determined using hi...

Journal of Proteomics & Bioinformatics, 2015

Paraquat (PQ) has been one of the most widely used herbicides in the world. PQ, when ingested, is... more Paraquat (PQ) has been one of the most widely used herbicides in the world. PQ, when ingested, is toxic to humans and may cause acute respiratory distress syndrome. To investigate molecular perturbation in lung tissues caused by PQ, Sprague Dawley male rats were fed with PQ at a dose of 25 mg/kg body weight for 20 times in four weeks. The effects of PQ on cellular processes and biological pathways were investigated by analyzing proteome in the lung tissues in comparison with the control. Among the detected proteins, 321 and 254 proteins were over-represented and under-represented, respectively, in the PQ-exposed rat lung tissues in comparison with the no PQ control. All over-and under-represented proteins were subjected to Ingenuity Pathway Analysis to create 25 biological networks and 38 pathways of interacting protein clusters. Over-represented proteins were involved in the C-jun-amino-terminal kinase pathway, caveolae-mediated endocytosis signaling, cardiovascular-cancer-respiratory pathway, regulation of clathrin-mediated endocytosis, non-small cell lung cancer signaling, pulmonary hypertension, glutamate receptor, immune response and angiogenesis. Under-represented proteins occurred in the p53 signaling pathway, mitogen-activated protein kinase signaling pathway, cartilage development and angiogenesis inhibition in the PQ-treated lungs. The results suggest that PQ may generate reactive oxygen species, impair the MAPK/p53 signaling pathway, activate angiogenesis and depress apoptosis in the lungs.

Korean Journal of Environmental Agriculture

BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more d... more BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more difficult to simultaneously analyze multiple polar pesticides. Diquat, paraquat, and chlormequat are typical examples of highly polar pesticides. The existing methods for the analysis of diquat, paraquat and chlormequat are complex and time consuming. Therefore, a simple, quick and effective method was developed in the represent study for simultaneous analysis of diquat, paraquat and chlormequat in animal products, meat and fat using UPLC-MS/MS. METHODS AND RESULTS: Sample extraction was carried out using acidified acetonitrile and water and reextracted with acidified acetonitrile and combine the extracts followed by centrifugation. The extract was then cleaned up with a HLB cartridge after reconstitution with acidic acetonitrile and water. The method was validated in quintuplicate at three different concentrations. The limits of detection (LOD) and quantification (LOQ) were 0.0015 and 0.005 mg/L, respectively. Matrix suppression effect was observed for all of the analytes. A seven point matrix matched calibration curve was constructed for each of the compound resulted excellent linearity with determination coefficients (R 2) ≥ 0.991. Accuracy and precision of the method was calculated from the recovery and repeatability and ranged from 62.4 to 119.7% with relative standard deviation less than 18.8%.

Korean Journal of Environmental Agriculture

BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. ... more BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. BPA is an endocrine disruptor. Residue of BPA in agricultural environments is a major concern. The objective of this study was to understand the characteristics of the uptake and distribution of BPA and its metabolites introduced into the agricultural environment to crops, and to use it as basic data for further research on reduction of BPA in agricultural products. METHODS AND RESULTS: This study established the analysis method of BPA and its metabolites in soil and crops, and estimated the intake of BPA and its metabolites from lettuce (Lactuca sativa) grown in sandy loam and loam soil, which are representative soils in Korea. The two major metabolites of BPA were 4-hydroxyacetophenone (4-HAP) and 4-hydroxybenzoic acid (4-HBA). BPA, 4-HAP and 4-HBA have been analyzed by using liquid chromatography tandem mass spectrometry (LC-MS/MS). These substances were detected in sandy loam and loam soil, indicating that certain portions of BPA were converted to 4-HAP and 4-HBA in the soil; however, it was observed that only 4-HBA migrated to lettuce through the roots into crops. CONCLUSION: The uptake residues showed the BPA and 4-HAP were not detected in lettuces grown on sandy loam (SL) and loam (L) soil treatments that were applied with of 10 ng/g, 50 ng/kg and 500 ng/g of BPA. However, the 4-HBA was detected at the level of 7 ng/g and 11 ng/g in the lettuce grown in sandy loam and loam soil that were treated with the 500 ng/g of BPA, respectively, while the 8 ng/g of 4-HBA was measured in the lettuce cultivated in the loam that was treated with 100 ng/g of BPA. This result presents that the BPA persisting in the soil of the pot was absorbed through the lettuce roots and then distributed in the lettuce leaves at the converted form of 4-HBA, what is the oxidative metabolite of BPA.

The Korean Journal of Pesticide Science

Korean Journal of Environmental Agriculture

BACKGROUND: Anthocyanins have been recognized as health-enhancing substances due to their antioxi... more BACKGROUND: Anthocyanins have been recognized as health-enhancing substances due to their antioxidant activity, anti-inflammatory, anticancer, and hypoglycemic effects. The objective was to identify anthocyanins-rich rice grains for the development of functional foods and/or functional food colorants METHODS AND RESULTS: Rice grains of one black and three red-hulled rice varieties were extracted with acidified 80% aqueous methanol. The antioxidant activity of the methanolic extracts was screened on TLC plates and in an in vitro assay using DPPH (1, 1-diphenyl-2-picrylhydrazyl) as a free radical source. Red-hulled rice varieties exhibited higher antioxidant activity (88%, 1 mg/mL) than black rice (67%, 1 mg/mL). Among the red-hulled varieties tested, rice variety SSALBYEO54 (901452) was the most active (72%, 0.5 mg/mL). Rice extracted anthocyanin compounds were analyzed by HPLC-DAD-FLD and LC-MS/MS. Red-hulled varieties comprised cyanidin-3-glucoside in addition to ferulic acid esters, apigenin and kaempferol glycosides. CONCLUSION(s): Anthocyanins identified in the black rice variety were cyanidin-7-O-galactoside, cyanidin-3-Oglucoside, cyanidin-3'-O-glucoside, cyanidin-5-O-glucoside, cyanidin-3, 7-O-diglucoside, cyanidin-3, 5-O-diglucoside and peonidin-4'-O-glucoside. The results of this study show that the black rice (IT212512) and red-hulled rice variety SSALBYEO54 (901452) contain notable antioxidant activity for potential use in nutraceutical or functional food formulations.

Journal of agricultural and food chemistry, Jan 11, 2018

Lung cancer is the second most prevalent cancer. Nonsmall cell lung cancer (NSCLC) is the most co... more Lung cancer is the second most prevalent cancer. Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer. The low efficacy in current chemotherapies impels us to find new alternatives to prevent or treat NSCLC. Rice bran oil is cytotoxic to A549 cells, a NSCLC cell line. Here, we identified 24-methylenecyloartanyl ferulate (24-mCAF) as the main component responsible for the cytotoxicity in A549 cells. An iTRAQ-based quantitative proteomics analysis revealed that 24-mCAF inhibits cell proliferation and activates cell death and apoptosis. 24-mCAF induces up-regulation of Myb binding protein 1A (MYBBP1A), a tumor suppressor that halts cancer progression. 24-mCAF inhibits the activity of AKT and Aurora B kinase, two Ser/Thr kinases involved in MYBBP1A regulation and that represent important targets in NSCLC. This study provides the first insight of the effect of 24-mCAF, the main component of rice bran oil, on A459 cells at the cellular and molecular levels.

Korean Journal of Environmental Agriculture, 2021

BACKGROUND: The concern over heavy metal(loid)s in arable land and agricultural products increase... more BACKGROUND: The concern over heavy metal(loid)s in arable land and agricultural products increases for public health in recent years. This study aims to identify transition characteristics of heavy metal(loid)s and to assess dietary risk in barley grown at the major producing districts in Korea. METHODS AND RESULTS: The soil and barley samples were collected from 38 locations around the major producing districts at Jeollabuk-do in Korea for the propose of examining the concentrations of heavy metal(loid)s. The 34 barley samples were separately purchased on the market for the same survey. The average concentration and range of arsenic (As), cadmium (Cd) and lead (Pb) in barley grown at the major producing districts in Korea were 0.

Korean Journal of Environmental Agriculture

BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit... more BACKGROUND: Pre-harvest interval and decline pattern of thiamethoxam were determined in kiwifruit using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study was carried out to propose import tolerance using OECD maximum residue limit (MRL) calculator for the export promotion of kiwifruit to Taiwan. METHODS AND RESULTS: The thiamethoxam residue in kiwifruit was determined by using the LC-TriQ-MS/ MS with the analytical process to set up the import tolerance under greenhouse conditions for Taiwan. Excellent linearity was observed for all of the analytes with a determination coefficient (R 2)≥0.99. The limit of quantification was determined to be 0.01 mg/kg for both thiame

Biomedical Chromatography, 2021

For export promotion, import tolerance of thiacloprid in strawberry was proposed using OECD Maxim... more For export promotion, import tolerance of thiacloprid in strawberry was proposed using OECD Maximum Residue Limit (MRL) calculator after conducting three different field trials. Pre-harvest interval (PHI) of residual pattern and degradation dynamic of thiacloprid in strawberry were determined using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Samples were extracted with acetonitrile and a mixture of salts and dilution was performed for purification. A six point matrix matched calibration curve was constructed which provided excellent linearity with coefficient of determination (R2 ) ≥ 0.9998. Detection and quantification limits were 0.003 mg/kg and 0.01 mg/kg respectively. The method was validated in quintuplicate at three different concentrations resulted acceptable recovery ranging from 80.86~101.71% with relative standard deviation (RSD) ≤ 6.50 among the three filed sites. The developed method was applied to the field treated sample harvested at different intervals. In PHI trial, the thiacloprid residues were ranged 0.24~0.70 mg/kg in the field site 1 (Nonsan), 0.16 ~ 0.50 mg/kg in the field site 2 (Sunchang), and 0.36 ~ 0.50 mg/kg in the field site 3 (Sacheon). Whereas, in the degradation trial, the observed residues were 0.03 ~ 0.81 mg/kg in the field site 1, and 0.02 ~ 0.48 mg/kg in the field site 2. Consequently, the import tolerance of thiacloprid in strawberry using OECD MRL calculator was proposed to 2 mg/kg, which is exactly same as the MRL established by Republic of Korea. In conclusion, the residue study supported to propose 2.0 mg/kg as a MRL of thiacloprid for strawberry..

Korean Journal of Environmental Agriculture, 2021

BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticide... more BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticides against fungal diseases in the world. However, benomyl is rapidly hydrolyzed in the environment after using to control plant diseases and has adverse effects by generating carbendazim, which is toxic to plants, humans, and the environment. METHODS AND RESULTS: In this study, the decomposition effect of carbendazim, a degradation product of benomyl was conducted in pot and field after making a prototype of benomyl-degrading microbial agent (BDMA). We found that the carbendazim-degrading microbial agent (CDMA) (10 5 , 10 6 , and 10 7 cfu/g soil) decomposed carbendazim by 50% or more in all the treatments, compared to the untreated control in the pot tests after four weeks. The effect of 100% decomposition of carbendazim was observed at 7 days after treatment, when the prototype of BDMA was apllied at 10-folds dilution in the field. The decomposition effect at more than 60% and plant growth promoting effect were observed after 7 days of the treatment, compared with the untreated group in the second field experiment,treated with commercially available concentrations of 500-folds and 1,000-folds. CONCLUSION(S): These results might represent that the BDMA would decompose carbendazim effectively, a de

Journal of proteomics & bioinformatics

Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of protein... more Mass spectrometry (MS) has been widely used for specific, sensitive and rapid analysis of proteins and has shown a high potential for bacterial identification and characterization. Type strains of four species of rhizobia and Escherichia coli DH5α were employed as reference bacteria to optimize various parameters for identification and classification of species of rhizobia by matrix-assisted laser desorption/ionization time-of-flight MS (MALDI TOF MS). The parameters optimized included culture medium states (liquid or solid), bacterial growth phases, colony storage temperature and duration, and protein data processing to enhance the bacterial identification resolution, accuracy and reliability. The medium state had little effects on the mass spectra of protein profiles. A suitable sampling time was between the exponential phase and the stationary phase. Consistent protein mass spectral profiles were observed for E. coli colonies pre-grown for 14 days and rhizobia for 21 days at 4°C ...

Korean Journal of Environmental Agriculture

BACKGROUND: Diquat dibromide is a fast-acting nonselective herbicide and plant growth regulator. ... more BACKGROUND: Diquat dibromide is a fast-acting nonselective herbicide and plant growth regulator. In this study, in order to understand the possibility of unintentional pesticide contamination in the following crops, the phytotoxicity and transition of diquat dibromide residue in soil into the following crops such as pepper, radish, lettuce and corn have been assessed through phytotoxicity trial and residual evaluation in the unintentional contamination of the higher residual diquat dibromide. METHODS AND RESULTS: The pepper, radish, lettuce and corn were cultivated in the sandy soil and loam soil where the 35 mg/kg and 90 mg/kg diquat dibromide were applied, respectively. Mild growth inhibition symptoms were observed in radish, lettuce and corn crops at the 90 mg/kg-diquat dibromide treatment on the 30 day of cultivation. Diquat dibromide was analyzed using liquid chromatography QTRAP (LC-MS/MS). The recovery rates of diquat dibromide from soil and crop were determined within range from 89.1 to 116.4% with relative standard deviation less than 14.7%. Diquat dibromide residues in soil were found to be 23.90-30.22 and 69.59-82.57 mg/kg from the 35 mg/kg and 90 mg/kg of diquat dibromide-treated soil, respectively after 30 days of crop cultivation. This result implicates that diquat dibromide did not convert to metabolites and remained mostly in the soil, even though it was partially decomposed during crop cultivation. In addition, the diquat dibromide in pepper and radish that were grown for 47 days, and lettuce and corn that were cultivated for 30 days were detected to be

Korean Journal of Applied Entomology, 2020

GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It i... more GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It is effective and selective against harmful algal blooms (HABs). HABs cause serious problems for public health and fishery industries. Algae that cause HABs include Microcystis spp., Anabaena spp., and Aphanizomenon spp. Blooms of toxin-producing Microcystis aeruginosa occur regularly in fresh water where is rich in nitrogen and phosphorus nutrients. Environmental fate studies are needed to investigate the degradation of GreenTD. In the present study, we studied the persistence of GreenTD (90% aqueous solution) in water and toxic effects GreenTD on M. aeruginosa and reduction of microcystin production in the culture media. GreenTD was added in the water pots and microcystis media tubes at levels of 25 g/0.1 ha (0.5 mg/kg) and 50 g/0.1 ha (1.0 mg/kg). Samples were collected after 1, 3, 5, 7 and 14 days. The residues of GreenTD and microcystins in water and the media were determined using hi...

Journal of Proteomics & Bioinformatics, 2015

Paraquat (PQ) has been one of the most widely used herbicides in the world. PQ, when ingested, is... more Paraquat (PQ) has been one of the most widely used herbicides in the world. PQ, when ingested, is toxic to humans and may cause acute respiratory distress syndrome. To investigate molecular perturbation in lung tissues caused by PQ, Sprague Dawley male rats were fed with PQ at a dose of 25 mg/kg body weight for 20 times in four weeks. The effects of PQ on cellular processes and biological pathways were investigated by analyzing proteome in the lung tissues in comparison with the control. Among the detected proteins, 321 and 254 proteins were over-represented and under-represented, respectively, in the PQ-exposed rat lung tissues in comparison with the no PQ control. All over-and under-represented proteins were subjected to Ingenuity Pathway Analysis to create 25 biological networks and 38 pathways of interacting protein clusters. Over-represented proteins were involved in the C-jun-amino-terminal kinase pathway, caveolae-mediated endocytosis signaling, cardiovascular-cancer-respiratory pathway, regulation of clathrin-mediated endocytosis, non-small cell lung cancer signaling, pulmonary hypertension, glutamate receptor, immune response and angiogenesis. Under-represented proteins occurred in the p53 signaling pathway, mitogen-activated protein kinase signaling pathway, cartilage development and angiogenesis inhibition in the PQ-treated lungs. The results suggest that PQ may generate reactive oxygen species, impair the MAPK/p53 signaling pathway, activate angiogenesis and depress apoptosis in the lungs.

Korean Journal of Environmental Agriculture

BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more d... more BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more difficult to simultaneously analyze multiple polar pesticides. Diquat, paraquat, and chlormequat are typical examples of highly polar pesticides. The existing methods for the analysis of diquat, paraquat and chlormequat are complex and time consuming. Therefore, a simple, quick and effective method was developed in the represent study for simultaneous analysis of diquat, paraquat and chlormequat in animal products, meat and fat using UPLC-MS/MS. METHODS AND RESULTS: Sample extraction was carried out using acidified acetonitrile and water and reextracted with acidified acetonitrile and combine the extracts followed by centrifugation. The extract was then cleaned up with a HLB cartridge after reconstitution with acidic acetonitrile and water. The method was validated in quintuplicate at three different concentrations. The limits of detection (LOD) and quantification (LOQ) were 0.0015 and 0.005 mg/L, respectively. Matrix suppression effect was observed for all of the analytes. A seven point matrix matched calibration curve was constructed for each of the compound resulted excellent linearity with determination coefficients (R 2) ≥ 0.991. Accuracy and precision of the method was calculated from the recovery and repeatability and ranged from 62.4 to 119.7% with relative standard deviation less than 18.8%.

Korean Journal of Environmental Agriculture

BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. ... more BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. BPA is an endocrine disruptor. Residue of BPA in agricultural environments is a major concern. The objective of this study was to understand the characteristics of the uptake and distribution of BPA and its metabolites introduced into the agricultural environment to crops, and to use it as basic data for further research on reduction of BPA in agricultural products. METHODS AND RESULTS: This study established the analysis method of BPA and its metabolites in soil and crops, and estimated the intake of BPA and its metabolites from lettuce (Lactuca sativa) grown in sandy loam and loam soil, which are representative soils in Korea. The two major metabolites of BPA were 4-hydroxyacetophenone (4-HAP) and 4-hydroxybenzoic acid (4-HBA). BPA, 4-HAP and 4-HBA have been analyzed by using liquid chromatography tandem mass spectrometry (LC-MS/MS). These substances were detected in sandy loam and loam soil, indicating that certain portions of BPA were converted to 4-HAP and 4-HBA in the soil; however, it was observed that only 4-HBA migrated to lettuce through the roots into crops. CONCLUSION: The uptake residues showed the BPA and 4-HAP were not detected in lettuces grown on sandy loam (SL) and loam (L) soil treatments that were applied with of 10 ng/g, 50 ng/kg and 500 ng/g of BPA. However, the 4-HBA was detected at the level of 7 ng/g and 11 ng/g in the lettuce grown in sandy loam and loam soil that were treated with the 500 ng/g of BPA, respectively, while the 8 ng/g of 4-HBA was measured in the lettuce cultivated in the loam that was treated with 100 ng/g of BPA. This result presents that the BPA persisting in the soil of the pot was absorbed through the lettuce roots and then distributed in the lettuce leaves at the converted form of 4-HBA, what is the oxidative metabolite of BPA.

The Korean Journal of Pesticide Science

Korean Journal of Environmental Agriculture

BACKGROUND: Anthocyanins have been recognized as health-enhancing substances due to their antioxi... more BACKGROUND: Anthocyanins have been recognized as health-enhancing substances due to their antioxidant activity, anti-inflammatory, anticancer, and hypoglycemic effects. The objective was to identify anthocyanins-rich rice grains for the development of functional foods and/or functional food colorants METHODS AND RESULTS: Rice grains of one black and three red-hulled rice varieties were extracted with acidified 80% aqueous methanol. The antioxidant activity of the methanolic extracts was screened on TLC plates and in an in vitro assay using DPPH (1, 1-diphenyl-2-picrylhydrazyl) as a free radical source. Red-hulled rice varieties exhibited higher antioxidant activity (88%, 1 mg/mL) than black rice (67%, 1 mg/mL). Among the red-hulled varieties tested, rice variety SSALBYEO54 (901452) was the most active (72%, 0.5 mg/mL). Rice extracted anthocyanin compounds were analyzed by HPLC-DAD-FLD and LC-MS/MS. Red-hulled varieties comprised cyanidin-3-glucoside in addition to ferulic acid esters, apigenin and kaempferol glycosides. CONCLUSION(s): Anthocyanins identified in the black rice variety were cyanidin-7-O-galactoside, cyanidin-3-Oglucoside, cyanidin-3'-O-glucoside, cyanidin-5-O-glucoside, cyanidin-3, 7-O-diglucoside, cyanidin-3, 5-O-diglucoside and peonidin-4'-O-glucoside. The results of this study show that the black rice (IT212512) and red-hulled rice variety SSALBYEO54 (901452) contain notable antioxidant activity for potential use in nutraceutical or functional food formulations.

Journal of agricultural and food chemistry, Jan 11, 2018

Lung cancer is the second most prevalent cancer. Nonsmall cell lung cancer (NSCLC) is the most co... more Lung cancer is the second most prevalent cancer. Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer. The low efficacy in current chemotherapies impels us to find new alternatives to prevent or treat NSCLC. Rice bran oil is cytotoxic to A549 cells, a NSCLC cell line. Here, we identified 24-methylenecyloartanyl ferulate (24-mCAF) as the main component responsible for the cytotoxicity in A549 cells. An iTRAQ-based quantitative proteomics analysis revealed that 24-mCAF inhibits cell proliferation and activates cell death and apoptosis. 24-mCAF induces up-regulation of Myb binding protein 1A (MYBBP1A), a tumor suppressor that halts cancer progression. 24-mCAF inhibits the activity of AKT and Aurora B kinase, two Ser/Thr kinases involved in MYBBP1A regulation and that represent important targets in NSCLC. This study provides the first insight of the effect of 24-mCAF, the main component of rice bran oil, on A459 cells at the cellular and molecular levels.