• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.254-268
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• 2011

Fenoxycarb, pyriproxyfen and methoprene are juvenile hormone mimic insecticide. These insecticides have been widely used for mosquito, fly, scale insects, and Lepidoptera. The purpose of this study was to develop a simultaneous determination procedure of fenoxycarb, pyriproxyfen and methoprene residues in crops using HPLC-UVD/MS. These insecticide residues were extracted with acetone from representative samples of four raw products which comprised brown rice, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and then n-hexane/dichloromethane partition was followed to recover these insecticides from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The analytes were quantitated by HPLC-UVD/MS, using a $C_{18}$ column. The crops were fortified with each insecticide at 3 levels per crop. Mean recovery ratios were ranged from 80.0 to 104.3% in four representative agricultural commodities. The coefficients of variation were less than 4.8%. Quantitative limit of fenoxycarb, pyriproxyfen, and methoprene was 0.04 mg/kg in crop samples. A HPLC-UVD/MS with selected-ion monitoring was also provided to confirm the suspected residues. The proposed simultaneous analysis method was reproducible and sensitive enough to determine the residues of fenoxycarb, pyriproxyfen and methoprene in the agricultural commodities.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.105-113
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• 2010

Ixeris dentata var. albiflora Nakai, a herbal plant, is often used to make a strong stomach as an antiphlogistic used when dyspepsia and to improve appetite in Korea and China. And also it is used for adult diseases such as diabetes and liver diseases as Korean traditional medicine. In this study, the composition and DPPH radical scavenging activities of the root of Ixeris dentata var. albiflora Nakai and its effects on cell viability on vero and chang cells were investigated. Moisture, crude ash, crude protein and crude lipid were 79.14, 2.49, 8.28 and 2.56 g/100 g respectively. The highest mineral content was K. The major free sugars were glucose, fructose and sucrose. Major fatty acid are linoleic acid, palmic acid and linolenic acid. Major amino acids were glutamic acid, arginine and aspartic acid and the total contents of amino acids were 28.12 mg/g. The methanol extracts were further fractionated with n-hexane, chloroform, ethylacetate, butanol and water to get an active fraction. In addition, cell viabilities in each fraction were determined. Methanol extract, butanol, and aqueous fraction showed strong survival rates in vero cell and chang cell viability test, and hexane, chloroform, and ethylacetate fraction were examined for toxin in a cell. The root of Ixeris dentata var. albiflora Nakai had scavenging activities against DPPH radicals in a dose-dependent assay. Ethylacetate fraction's SC50 was $6.8\{\mu}g/mL$, very strong DPPH radical scavenging activities, but water fraction did not show any activity.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.353-358
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• 2021

BACKGROUND: Prochloraz has been widely used as an imidazole fungicide on fruits and vegetables in Korea. Analytical approaches to evaluate prochloraz residues in herbal medicine are required for their safety management. In this study, we developed a GC-ECD method for quantitative determination of prochloraz in Platycodi Radix. The metabolite 2,4,6-trichlorophenol (2,4,6-T) was used as a target compound to evaluate total prochloraz residues as it is categorized to a representative residue definition of prochloraz. All residues containing 2,4,6-T were converted to 2,4,6-T and subjected to GC-ECD. METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining prochloraz and it metabolite 2,4,6-T in Platycodi Radix. Prochloraz and its metabolite 2,4,6-T residuals were extracted using acetone. The extract was diluted with and partitioned directly into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was decomposed to 2,4,6-T, and then the partitioned ion-associate was finally purified by optimized aminopropyl solid-phase extraction (SPE). The limits of quantitation of the method (MLOQs) were 0.04 mg/kg and 0.02 mg/kg, respectively for prochloraz and 2,4,6-T, considering the maximum residue level (MRL) of prochloraz as 0.05 mg/kg in Platycodi Radix. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (82.1-89.7%). Good reproducibilities were obtained (coefficient of variation < 2.8%), and the linearities of calibration curves were reasonable (r² > 0.9986) in the range of 0.005-0.5 ㎍/mL. CONCLUSION(S): The method developed in this study was successfully validated to meet the guidelines required for quantitative determination of pesticides in herbal medicine. Thus, the method could be useful to monitor prochloraz institutionally in herbal medicine.

• Clean Technology
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• v.25 no.4
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• pp.311-315
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• 2019

The cation extraction and impurity separation were studied in order to investigate the recyclability of a slag produced from the steel refinery industry. Two types of slag (Slag-A, B) were collected and characterized in this study. The initial characterization by X-ray diffraction (XRD) and X-ray fluorescence (XRF) confirmed the existence of various kinds of ions in the slag such as Ca²⁺ (30 ~ 40%), Fe³⁺ (20 ~ 30%), Si⁴⁺ (15%), Al³⁺ (10%), Mn²⁺ (7%), and Mg²⁺ (3 ~ 5%). Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis on the extracted slag using 2 M HCl as a solvent indicated that a higher concentration of Ca²⁺ was extracted as the S/L ratio was increased. The Ca²⁺ extraction concentration were found to be 8,940 mg L^-1 (Slag-A) and 10,690 (Slag-B) mg L^-1 when the S/L ratio for Ca²⁺ extraction was 0.1. However, the extract was strongly acidic ( < pH 1) at 0.1 S/L. Also the other ions (impurities) were extracted simultaneously in addition to Ca²⁺. To increase the purity of Ca²⁺ in order to transform the slag to a high value resource, a pH-swing was conducted. The impurities tended to precipitate at higher rate as the pH was increased. Notably, the Ca²⁺ rapidly precipitated above a certain pH and at a pH of 10.5, while the selectivity of Ca²⁺ was over 99%. It is expected that the aqueous solution in which high contents of Ca²⁺ was selectively dissolved in this study would be suitable for the carbonation process for reducing CO₂ and for the production of calcium carbonate.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.118-124
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• 2009

Esterase EM2L8 gene isolated from deep sea sediment was expressed in Escherichia coli BL21 (DE3) and the esterase activity of the cell-free extract was assayed using p-nitrophenyl butyrate-spectrophotometric method. Its optimum temperature was $40-45^{\circ}C$ and 45% activity of the maximum activity was retained at $15^{\circ}C$. The activation energy at $15-45^{\circ}C$ was calculated to be 4.9 kcal/mol showing that esterase EM2L8 was a typical cold-adapted enzyme. Enzyme activity was maintained for 6 h and 4 weeks at $30^{\circ}C$ and $4^{\circ}C$, respectively. When each ethanol, methanol, and acetone was added to the reaction mixture to 15% concentration, enzyme activity was maintained. In the case of DMSO, enzyme activity was kept up to 40% concentration. (S)-4-Chloro-3-hydroxy butyric acid is a chiral intermediate for the synthesis of Atorvastatin, a hyperlipemia drug. When esterase EM2L8 (40 U) was added to buffer solution (1.2 mL, pH 9.0) containing ethyl-(R,S)-4-chloro-3-hydroxybutyrate (38 mM), it was hydrolyzed into 4-chloro-3-hydroxy butyric acid with a rate of $6.8\;{\mu}mole/h$. The enzyme hydrolyzed (S)-substrate more rapidly than (R)-substrate. When conversion yield was 80%, e.e.s value was 40%. When DMSO was added, hydrolysis rate increased to $10.4\;{\mu}mole/h$. The plots of conversion yield vs e.e.s in the presence or absence of DMSO were almost same, implying that the reaction enantioselectivity was not changed by the addition of DMSO. Taken together, esterase EM2L8 had high activity and stability at low temperatures as well as in various organic solvents/aqueous solutions. These properties suggested that it could be used as a biocatalyst in the synthesis of useful pharmaceuticals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.480-486
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• 2004

Despite many therapeutic advances in the understanding of the processes in carcinogenesis, overall mortality statistics are unlikely to change until there is reorientation of the concepts for the use of natural products as new anticarcinogenic agents. In this study, we investigated the anticarcinogenic activity, antioxidant and DPPH scavenging activity of Sargassum fulvellum (SF). SF was extracted with methanol, which was further fractionated into five different types: hexane (SFMH), ethylether (SFMEE), ethyl acetate (SFMEA), butanol (SFMB) and aqueous (SFMA) partition layers. We determined the cytotoxic effect of these layers on human cancer cells by MTT assay. Among various partition layers of SF, at starting concentration of 100 $\mu\textrm{g}$/mL, SFMEE showed very high cytotoxicity which were 92, 90 and 84% and kept high throughout 5 concentration levels sparsed by 100 $\mu\textrm{g}$/mL against all three human cancer cell lines: HepG2, HT-29 and HeLa. SFMEA showed a low cytotoxicity at the beginning concentration level, but as the concentration became denser, growth inhibition effect of cancer cell lines started to increase and at 500 $\mu\textrm{g}$/mL, it hit the highest, which were 91, 96 and 98% against the same three cell lines as above. We observed QR induced effect in all fraction layers of SF. SFMEE showed similar tendensy of QR induced effect as did against cytotoxicity. The QR induced effect of SFMEE on HepG2 cells at 25 $\mu\textrm{g}$/mL concentration indicated 3 times higher than the control value of 1.0 and SFMH tended to be concentration-dependent on HepG2 cells. At 100 $\mu\textrm{g}$/mL, the QR induced effects resulted a ratio, which was 2.5 times higher than the control value. In search for antioxidation effects of SF extract and partition layer, the reducing activity on the 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging potential was sequentially screened. The SFM has similar antioxidant activity as to BHT and vitamin C groups.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.223-227
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• 2008

The aerial parts of Sajabalssuk (Artemisia princeps PAMPANINI, Sajabalssuk) was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three cycloartane-type triterpnoids and one ursane-type triterpenoid were isolated through the repeated silica gel, ODS and Sephadex LH-20 column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the triterpenoids were determined as wrightial (1), wrightial acetate (2), 27-norcycloart-20(21)-ene-25-al-3${\beta}$-ol acetate (3) and ursolic acid (4). No report has been found for isolation of compound 3 in the literature so far, and compounds 1, 2 and 3 were the first to be isolated from Sajabalssuk (Artemisia princeps PAMPANINI, Sajabalssuk). Also, compound 1 showed Acyl-CoA:Cholesterol acyltransferase (hACAT-1) and hACAT-2 inhibitory activity with the $IC_{50}$ values of 33.0 and 45.0 ${\mu}g/ml$, respectively. Compounds 2 and 3 inhibited hACAT-1 activity with the $IC_{50}$ values of 12.0 and 16.0 ${\mu}g/ml$, respectively.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.142-147
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• 2008

Nuruk is the Korean traditional Koji that contains various microorganisms and has been used to make the traditional fermented foods including alcoholic beverages. Rhizopus oryzae KSD-815 was isolated from the alcohol-fermenting Nuruk used for manufacturing traditional alcohol. In this study, the authors reported the isolation and identification of four lipids from the Nuruk (Rhizopus oryzae KSD-815) that inoculated wheat with Rhizopus oryzae KSD-815. The dried and powdered Nuruk (Rhizopus oryzae KSD-815) were extracted three times at room temperature with 80% aqueous MeOH. The extracts were partitioned with EtOAc, n-BuOH, and water, successively. The EtOAc extract was suspended in 80% MeOH and partitioned repeatedly with n-hexane. From the n-hexane fraction, four lipids were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, GC and MS, the chemical structures of the compounds were determined as linolenic acid methyl ester (1), palmitic acid methyl ester (2), linoleic acid (3), palmitic acid (4). Cytotoxicity was evaluated in huamn breast cancer cells, MDA-MB-231 and human hepatocarcinoma, SK-HEP-1 cells using MTT assay. Exposure of compounds 1 and 3 led to a dose-dependent inhibition of cell viability in both cancer cell lines. In addition, treatment of RAW264.7 cells with compound 3 caused inhibition of lipopolysaccharide/interferon-${\gamma}$-induced nitric oxide production.

• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.199-205
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• 2005

This study was carried out to investigate the effect of 70% ethanol extract and each fraction from Rhododendron brachycarpum D. Don leaves on cytotoxicity, anticancer, genotoxicity and immunological activity in vitro bioassay. Cytotoxicity for human normal cells (HEL299 and Chang) of the samples was shown below 35% in 0.5 mg/ml concentration of samples except aqueous fraction by SRB assay. DNA damage on the Chang cell of the samples alone in comet assay was observed very weak damage activity even in high concentration (1 mg/ml) of the samples. The anticancer effect of the samples on human cancer cell lines (A549, AGS, Hep3B, MCF7) was indicated that the cancer cells were inhibited gradually in proportion to the increase of the concentration of the samples by MTT assay. The growth of the Raji and Jurkat cells were hastened by adding butanol fraction among the samples. In the genotoxicity on $H_2O_2-induced$ DNA damage in Chang cells using alkaline comet assay, most of samples were shown a strong protective activity from DNA OTM values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.7-15
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• 2004

This research was designed to investigate the antioxidant activity of red cabbage (Brassica oleracea L., BO) fractions on the liposomes consisted of L-$\alpha$-dilinoleoylphosphatidylcholine (DLPC-liposome) and the tyrosinase activity of BO fractions. The methanol extract of BO (BOM) was fractionated into five different partition layers: hexane (BOMH), ethylether (BOMEE), ethylacetate (BOMEA), butanol (BOMB) and aqueous (BOMA) layers. The antioxidant activities of BOM fractions toward oxidized DLPC-liposome were examined by spectrophotometry measuring oxidized conjugated dines. The antioxidant activities of BOMEE and BOMEA fractions toward oxidized DLPC-liposomes were similar to the antioxidant activities of $\alpha$-tocopherol and weaker than that of BHT. The synergy effects of antioxidation of BOMEE and BOMEA fractions added with vitamin C and $\alpha$-tocopherol had even stronger antioxidant activities than the fractions without vitamin C and $\alpha$-tocopherol. These results showed that the fractions of BOMEE and BOMEA could be developed as a potent antioxidant. Out of five different partition layers of BOM fractions, BOMEA exhibited the strongest tyrosinase activity of 94% at a concentration of 40 $\mu\textrm{g}$/mL. This result suggests BOMEA fractions inhibit the foramation of melanin and therefore can be used as the inhibitor of melanin synthesis. Results of antioxidant activity and tyrosinase inhibition indicate that useful bioactive substances exist in BOMEE and BOMEA fractions. Both fractions from BO (red cabbage) have the potential of being developed into health related products.