• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.284-287
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• 2005

The flowers of Chrysanthemum boreale Makino were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with n-hexane, EtOAc, n-BuOH and $H_2O$. Two compounds from the n-hexane fraction and one glucoside from the n-BuOH fraction were isolated through the repeated silica gel and ODS column chromatographies. From the result of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as ${\beta}-sitosterol$ (1), phytol (2) and zingerone $4-O-{\beta}-D-glucopyranoside$ (3). Compounds 2 and 3 were isolated for the first time from this plant.

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.147-156
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• 2013

The objectives of this study were to investigate the effect of Lactobacillus paracasei subsp. tolerans JG22 isolated from pepper leaf jangajji on the mutagenic activity of N-methyl, N'-nitro, N-nitrosoguanidine (MNNG) and 2-nitrofluene (2-NF) and to evaluate the effect of physico-chemical pretreatment on the antimutagenic activity of the strain. The viable cells of JG22 strain displayed a significantly high (p <0.05) antimutagenic activity against both mutagens tested. The antimutagenic effect of JG22 strain seems to be positively correlated with the amounts of the cells in the incubation time. This strain produced the antimutagenic activity of the maximum levels after preincubation for 30 min. The binding of this strain against the mutagenic compounds might be mainly present in the cell wall fraction rather than the cytosol fraction. Pretreatment with proteolytic enzymes and simulated gastric and intestinal juices and at different pH values had no significant effect on two mutagens removal by the viable cells. However, the binding activity of the mutagen by the strain seems to be affected by heating, enzymes including $\alpha$-amylase and lysozyme, divalent ions, and sodium metaperiodate. Thus, carbohydrates consisting of the cell walls may be important elements responsible for the binding of MNNG and 2-NF by this strain. In conclusion, the binding of the mutagens to cells of JG 22 strain may play a vital role in suppressing the process of mutagenesis induced by mutagens.

• Journal of Applied Biological Chemistry
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• v.48 no.1
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• pp.35-37
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• 2005

Campsis grandiflora K. Schum. flower was extracted with 80% aqueous MeOH, and concentrated extract was successively partitioned with EtOAc, n-BuOH, and $H_2O$. From n-BuOH fraction, two cyclohexylethanoids were isolated through repeated silica gel and Sephadex LH-20 column chromatographies. Based on physico-chemical data obtained from NMR, MS, and IR, chemical structures of compounds were determined as 1,4-dihydroxy-3,4-(epoxyethano)-5-cyclohexene (1) and cornoside (2). These compounds were isolated for the first time from C. grandiflora K. Schum flower.

• Membrane and Water Treatment
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• v.4 no.2
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• pp.109-126
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• 2013

Surface modification by low-pressure ammonia ($NH_3$) plasma on commercial thin-film composite (TFC) membranes was investigated in this study. Surface hydrophilicity, total surface free energy, ion exchange capacity (IEC) and zeta (${\zeta}$)-potentials were determined for the TFC membranes. Qualitative and quantitative analyses of the membrane surface chemistry were conducted by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy. Results showed that the $NH_3$ plasma treatment increased the surface hydrophilicity, in particular at a plasma treatment time longer than 5 min at 50 W of plasma power. Total surface free energy was influenced by the basic polar components introduced by the $NH_3$ plasma, and isoelectric point (IEP) was shifted to higher pH region after the modification. A ten (10) min $NH_3$ plasma treatment at 90 W was found to be adequate for the TFC membrane modification, resulting in a membrane with better characteristics than the TFC membranes without the modification for water treatment. The thin-film chemistry (i.e., fully-aromatic and semi-aromatic nature in the interfacial polymerization) influenced the initial stage of plasma modification.

• Journal of Applied Biological Chemistry
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• v.49 no.3
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• pp.95-100
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• 2006

Brown rice with a giant embryo (GE) was observed on the quality parameters of the enlargement of embryo, nutritional components, and physical properties, in comparison to normal embryo brown rice (NE). Also, the effects of germination on the quality parameters were examined. GE embryo was approximately 2.68 times larger than of NE rice. Total free sugars were significantly higher in GE rice (71.96 vs. 41.17 mg/100 g), and germinated rice increased in fructose, but decreased in sucrose and maltose. No significant difference in mineral contents was found in GE and NE rice and their germinated rice, whereas a significant increment was observed on reducing sugars and gamma-amino butyric acid (GABA) contents in GE rice. The lower water absorption index (WAI) of GE rice resulted in relatively lower pasting viscosity, whereas the increased WSI in germinated rice might be attributable to the significant increment of soluble components in GE rice.

• Journal of Applied Biological Chemistry
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• v.51 no.4
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• pp.165-168
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• 2008

A processed Aconiti tuber (Korean name, Kyeong-Po Buja) was extracted with 80% aqueous EtOH, and the concentrated extract was partitioned with EtOAc and water ($H_2O$). From the EtOAc fraction, two flavonoids were isolated through repeated silica gel column chromatographies. From the result of physico-chemical data including NMR, mass spectrometry and IR, the chemical structures of the compounds were determined to be liquiritin (1) and liquiritigenin (2). This is the first study to isolate flavonoids (1) and (2) from the processed Aconiti tuber.

• Macromolecular Research
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• v.13 no.4
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• pp.339-343
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• 2005

Microbial hydrogel was prepared by ${\gamma}-irradiation$ of poly(${\gamma}-glutamic acid$) (PGA) which was produced from Bacillus subtilis BS 62 and it's physico-chemical characteristic was examined. The hydrogel, prepared from 10% PGA with the dose of 48 kGy, was swollen up to 1,370 times of specific water content as dry weight basis. The hydrogels obtained above the dose of 48 kGy appeared to have higher compressive strength but lower specific water content. The period to reach a swelling equilibrium for the hydrogel in deionized water at the temperature range of 4 to $45^{\circ}C$ was about 10 h. The swollen hydrogel was shrunk in ionic solutions with the increase of ionic strength, and the rate of shrinkage was greater in calcium chloride solution than in sodium chloride. Specific water content of the hydrogel was quickly decreased at $80^{\circ}C$, showing a thennally hydrodegradable property.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.483-486
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• 2021

Catalytic ozonation of methyl ethyl ketone (MEK) has been examined over mesoporous MnO_x/Al₂O₃ (MA) catalysts developed by a solvent deficient method using two different manganese precursors including manganese chloride (C) and manganese sulfate (S) at room temperature. The maximum catalytic activities of MA with C (MEK removal efficiency and ozone decomposition of 98.4 and 93.7%, respectively) were higher than those of MA with S (MEK removal efficiency and ozone decomposition of 96 and 68%, respectively). Also the catalytic stability of MA with C was much higher than that of MA with S. The physico-chemical properties of catalysts are well correlated with the activity results, which confirmed that fine dispersion of MnO_x species with high ratios of Mn³⁺/Mn⁴⁺ and more acid sites are attributed to the higher catalyst stability for the MA-C catalyst.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.385-392
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• 2021

In this study, impact of Co proportion and calcination temperature of ceria on the Co/CeO₂ was analyzed by comparing nitrogen monoxide oxidation performance of various catalysts and their physico-chemical properties. The structural properties of each catalyst were studied by XRD and BET analysis, and the surface crystal states of cobalt were proposed according to the surface density. Oxidation states of elements were observed through Raman and XPS analysis, and the relationship between typical oxidation states and nitrogen monoxide oxidation performance was designed. Through H₂-TPR, oxygen-transferring capacity due to changes in the characteristics of catalysts were identified, and activation sites (Co³⁺) for oxidation were suggested.

• Journal of the Korean Ceramic Society
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• v.53 no.4
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• pp.417-428
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• 2016

In this review, an attempt is made to calculate one-dimensional (1-D) electron density profiles from experimentally determined (00l) XRD intensities and possible structural models as well in an effort to understand the collective intracrystalline structures of intercalant molecules of two-dimensional (2-D) nanohybrids with heterostructures. 2-D ceramics, including layered metal oxides and clays, have received much attention due to their potential applicability as catalysts, electrodes, stabilizing agents, and drug delivery systems. 2-D nanohybrids based on such layered ceramics with various heterostructures have been realized through intercalation reactions. In general, the physico-chemical properties of such 2-D nanohybrids are strongly correlated with their heterostructures, but it is not easy to solve the crystal structures due to their low crystallinity and high anisotropic nature. However, the powder X-ray diffraction (XRD) analysis method is thought to be the most powerful means of understanding the interlayer structures of intercalant molecules. If a proper number of well-developed (00l) XRD peaks are available for such 2-D nanohybrids, the 1-D electron density along the crystallographic c-axis can be calculated via a Fourier transform analysis to obtain structural information about the orientations and arrangements of guest species in the interlayer space.