• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.323-330
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• 1998

Cyclodextrin glucanotransferase (CGTase) was purified from the culture broth of the Bacillus firmus var. alkalophilus, using ultrafiltration, starch adsorption/desorption, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephacryl HR-100. The molecular weight of the purified enzyme was determined as 77,000 by SDS-PAGE. The optimum pH and temperature for the CD synthesis were 6.0 and 5$0^{\circ}C$, respectively. The activity of this enzyme was stably kept at the range of pH 6.0～9.5 and up to 5$0^{\circ}C$. However, in the presence of $Ca^{2+}$, the optimum temperature for CD synthesis was shifted 55~6$0^{\circ}C$ and this enzyme was stable up to 6$0^{\circ}C$ because of the stabilizing effect of $Ca^{2+}$. The purified CGTase produced CDs with high conversion yields of 45~51% from sweet potato starch, com starch and amylopectin as substrate, especially, and the product ratio of $\beta$-CD to ${\gamma}$-CD was obtained at range of from 5.8:1 to 8.4:1 according to the kind of substrate. The purified enzyme produced mainly $\beta$-CD without accumulation of $\alpha$-CD during enzyme reaction using various starches as the substrate, indicating that the purified enzyme is the typical $\beta$-CGTase. The purified CGTase produced 25 g/l of CDs from 5.0% (w/v) liquefied com starch and the conversion yield of CDs was 50%, and the content of $\beta$-CD was 84% of total CDs after 8 hours under the optimum reaction condition.ion.

• Analytical Science and Technology
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• v.24 no.2
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• pp.69-77
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• 2011

Ethylene glycol (EG) is produced commercially in large amounts and is widely used as antifreeze or deicing solution for cars, boats, and aircraft. EG poisoning occurs in suicide attempts and infrequently, either intentionally through misuse or accidental as EG has a sweet taste. EG has in itself a low toxicity, but is in vivo broken down to higher toxic organic acids which are responsible for extensive cellular damage in various tissues caused principally by the metabolites glycolic acid and oxalic acid. The most conclusive analytical method of diagnosing EG poisoning is determination of EG concentration. However, victims are sometimes admitted at a late stage to hospitals or died during emergency treatment like a gastric lavage or found rotten dead, when blood EG concentrations are low or not detected. Therefore, in this study, the identification of EG was not only performed by gas chromatograpyc-mass spectrometry (GC-MS) following derivatization but also further toxicological analyses of metabolites, glycolic acid (GA) and oxalic acid (OA), were performed by ion chromatography in various biological specimens. A ranges of blood concentrations (3 cases) was $10\sim2,400\;{\mu}g/mL$ for EG, $224\sim1,164\;{\mu}g/mL$ for GA and ND $\sim40\;{\mu}g/mL$ for OA, respectively, In other biological specimens (liver, kidney, bile and pleural fluid), a range of concentrations (3 cases) was ND $\sim55,000\;{\mu}g/mL$ for EG, ND $\sim1,124\;{\mu}g/mL$ for GA and ND $\sim60\;{\mu}g/mL$ for OA, respectively. Liver and kidney tissues were recommended specimens including blood because OA, a final metabolite of EG, was identified large amounts in these despite no detectable EG caused by some therapy.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.311-322
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• 2012

Restoration materials used to investigate effects of fluorine such as enamel strengthening and anti-caries effects in several types of dental restoration materials were five kinds including Ionoseal(VOCO GmbH, Cuxhaven, Germany), Fuji Filling LC(GC Co. Tokyo, Japan), Quadrant Universal LC(CAVEX Holland BV, Netherlands), PermaCem$^{(R)}$(DMG, Hamburg, Germany) and Dyract$^{(R)}$ AP(Dentsply GmbH, Germany), and the amount of fluorine-releasing was measured with ICS-5000 Reagent-FreeTM Ion Chromatography(RFICTM, Dionex, U.S.A.). The results of this study are as follows. 1. In all types of restoration materials, the amount of fluoride-releasing was reduced with time passage and it was declined sharply to show significance in four weeks. Fuji Filling LC(12.445PPM) or resin-reinforced glass ionomer and PermaCem$^{(R)}$(16.121PPM) or compomer were found to release fluorine for a long term(P<.001). 2. Ionoseal(0.887PPM) or glass ionomer and Quadrant Universal LC(0.957PPM) or composite resin released a few fluorine of 1PPM or less than 1PPM after one week, and Dyract$^{(R)}$ AP or compomer released fluorine of 8.631PPM in one week and its amount of releasing decreased dramatically in two and four week by recording 0.175PPM and 0.116PPM, respectively. Therefore, the effect of releasing fluorine in four weeks was observed to be poor (P<.001). 3. Fuji Filling LC or resin-reinforced glass ionomer and PermaCem$^{(R)}$ or compomer released fluorine of 33.372 and 1.902PPM, respectively in one week and their amount of releasing increased to be 36.371 and 18.223PPM, respectively in two weeks. So, their amount of fluorine-releasing recorded the highest levels in two weeks(P<.001).

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.254-262
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• 1980

A series of experiment were carried out to separate the factor accelerating the lysis of cell wall of $Saccharomyces\;sak{\acute{e}}$ from the preparation of crude zymolyase obtained from Arthrobacter luteus. An attempt was also made to purify the enzyme which is essential for the study on the separation of the factor. The results are summarized as follows: 1. Crude zymolyase was fractionated 5 peaks $(A{\sim}E)$ containing three peaks $(A{\sim}C)$ passed through the column by the chromatography on Biogel CM-30. 2. Among the five peaks, peak E (protease fraction) was found to contain the factor accelerating the lytic activity of the zymolyase. 3. L-c fraction purified in almost free form from the nonlytic ${\beta}-1$, 3-glucanase, protease and inert protein by the affinity adsorption chromatography with Sephadex G-75 gel was obtained from zymolyase fraction (peak D). When it was subjected to polyacrylamide gel disc electrophoresis, only one clear protein band was observed at pH 4. 5, but still detected two or more band at pH 8. 3.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.482-494
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• 1994

Most of carotenoprotein complexes have been extracted by using buffered solutions. However, in this study carotenoprotein from the muscle of Blue mussel(Mytilus edulis) was extracted by a detergent such as Triton X-100. It was purified and characterized by $20\%$ (w/v) $(NH_4)_2SO_4$, DEAE-cellulose ion exchange and Sephacryl S-300 gel filtration. The carotenoprotein(${\lambda}_{max}=462nm$) had an approximate M. W. of 372KDa(gel filtration). SDS-PAGE analysis of the carotenoprotein indicated the presence of four polypeptides of 60KDa($23.70\%$), 46.9KDa($9.14\%$), 26KDa($49.14\%$) and 13KDa($18.02\%$). Carotenoprotein denaturated by treatment with SDS to a final concentration of $0.2\%$ (w/v) caused a hypsochromic shift of ${\lambda}_{max}$ from 462nm to 456nm. The carotenoprotein contained lipids as structure units. The amino acid composition of the carotenoprotein contained large essential amino acid amounts of $62.8\%$, and the content of threonine($35.9\%$) was higher than other amino acids, but histidine, methionine and proline were not present. In the carotenoprotein, the major fatty acids were $C_{16:4},\;C_{16:0},\;C_{20:5}\;and\;C_{22:6}$. The percentages of polyunsaturated fatty acids($62.4\%$) were higher compared to other fatty acids(saturated fatty acids $19.6\%$, monounsaturated fatty acids $18.0\%$). Carotenoid was extracted from the carotenoprotein by acetone and it was separated into five different components by preparative TLC(benzene:petroleum ether:acetone=69:17:14). The major components of carotenoid were mytiloxanthin($74.79\%$) and 3,4,3'- trihydroxy-7',8'-didehydro-${\beta}$-carotene($18.26\%$), and they were at least presented as prosthetic groups of carotenoprotein.

• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.51-59
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• 2001

Column and box tests were performed to investigate the removal efficiency of NAPL using the surfactant enhanced flushing In heterogeneous medium. Homogeneous Ottawa sand and heterogeneous soil were used to verify the increase of remediation efficiency for the surfactant enhanced flushing in column test. Box tests with two different heterogeneous sub-structure were performed to quantify the capability of the surfactant enhanced flushing as a remediation method to remove NAPL from the heterogeneous medium. Two different grain size sand layers were repeated in the box to simulate the heterogeneous layer formation and the modified fault structure was built to simulate the fault system in the box. O-xylene as a LNAPL and PCE as a DNAPL were used and oleamide as a non-ionic surfactant. The maximum NAPL effluent concentration with 1% oleamide flushing in the homogeneous column test increased about 460 times compared to that with only water flushing and about 250 times increased in the real soil column test. In heterogeneous medium, the maximum effluent concentration increased about 150 times in 1% oleamide flushing and most of NAPL were removed from the box within 8 pore volume flushing, suggesting that the removal efficiency increased very much compared to in only water flushing. Results investigated the capability of the surfactant enhanced remediation method to remove NAPL even in heterogeneous medium.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.202-208
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• 2012

A high-performance liquid chromatographic (HPLC) method was developed to determine residues of cyromazine, a triazine insecticide, in agricultural commodities. Cyromazine was extracted with 90% aqueous methanol from representative crops which comprised brown rice, oyster mushroom, oriental melon, watermelon, and Chinese cabbage. Following to evaporation of methanol in the extract, the aqueous concentrate was acidified to form the protonated cyromazine. Dichloromethane partition was then applied to remove nonpolar co-extractives in the aqueous phase. Strong cation-exchange chromatography using Dowex 50W-X4 resin was employed for final purification of the extract. Cyromazine was successfully separated on a Zorbax SB-Aq $C_{18}$ column showing high retention for polar compounds. Cyromazine was sensitively quantitated by ultraviolet absorption at 214 nm. Limit of quantitation (LOQ) of the method was 0.04 mg/kg irrespective of sample types. Each crops were fortified at 3 different concentrations of cyromazine for recovery test. Mean recoveries from samples fortified at LOQ~2.0 mg/kg in triplicate ranged 80.2~103.3% in five agricultural commodities. Relative standard deviations in recoveries were all less than 6%. A selected-ion monitoring LC/MS method with electrospray ionization in positive-ion mode was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to routinely determine and inspect the residue of cyromazine in agricultural commodities.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.565-578
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• 1992

It has been suggested that Hg$^{2+}$-promoted reaction of a series of cis-[Co(en)$_2$(L)Cl]$^{2+}$ (en = 1,2-diaminoethane) with L = NH$_3$, NH$_2$CH$_3$, glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, and NH$_2$CH$_2$CN proceeds by dissociative interchange(I$_d$) mechanism from kinetic data, circular dichroism spectra, analyses of products, and the values of m(Grunwald-Winstein plot) using Y (solvent ionizing power) in aqueous solution and in mixed aqueous-organic solvent. It has been found that chloride replacement by water (aquation) for the series with L = NH$_3$ and NH$_2$CH$_3$ and chelation of ligand L to Co(Ⅲ) for the series with L = glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, and NH$_2$CH$_2$CN occurs, respectively. The rate constants on Hg$^{2+}$-induced reaction of the series except cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ were increased with increasing the contents of ethanol in mixed water-ethanol solvents. In mixed water-30${\%}$ organic solvents, the rate constants of the series except cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ have also been measured in the order 30${\%}$ 2-propanol-water > 30${\%}$ ethanol-water > water. However, the rate constants of cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$ were reversed. The rate constants of the series with L= NH$_3$ and NH$_2$CH$_3$ were related to ligand field parameter (${\Delta}$), but those of the series with L = glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$, NH$_2$CH$_2$CN were not. The reaction between the series and Hg2+ in aqueous media containing NO$_3^-$ has been investigated. The results for the reaction do not alter the mechanism, but the rate only was altered.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.302-313
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• 2008

The purposes of this study are to investigate the concentration levels of fine particles, so called PM$_{2.5}$, to identify the affecting sources, and to estimate quantitatively the source contributions of PM$_{2.5}$. Ambient air sampling was seasonally carried out at two sites in Pohang(a residential and an industrial area) during the period of March to December 2003. PM$_{2.5}$ samples were collected by high volume air samplers with a PM$_{10}$ Inlet and an impactor for particle size segregation, and then determined by gravimetric method. The chemical species associated with PM$_{2.5}$ were analyzed by inductively coupled plasma spectrophotometery(ICP) and ion chromatography(IC). The results showed that the most significant season for PM$_{2.5}$ mass concentrations appeared to be spring, followed by winter, fall, and summer. The annual mean concentrations of PM$_{2.5}$ were 36.6 $\mu$g/m$^3$ in the industrial and 30.6 $\mu$g/m$^3$ in the residential area, respectively. The major components associated with PM$_{2.5}$ were the secondary aerosols such as nitrates and sulfates, which were respectively 4.2 and 8.6 $\mu$g/m$^3$ in the industrial area and 3.7 and 6.9 $\mu$g/m$^3$ in the residential area. The concentrations of chemical component in relation to natural emission sources such as Al, Ca, Mg, K were generally higher at both sampling sites than other sources. However, the concentrations of Fe, Mn, Cr in the industrial area were higher than those in the residential area. Based on the principal component analysis and stepwise multiple linear regression analysis for both areas, it was found that soil/road dust and secondary aerosols are the most significant factors affecting the variations of PM$_{2.5}$ in the ambient air of Pohang. The source apportionments of PM$_{2.5}$ were conducted by chemical mass balance(CMB) modeling. The contributions of PM$_{2.5}$ emission sources were estimated using the CMB8.0 receptor model, resulting that soil/road dust was the major contributor to PM$_{2.5}$, followed by secondary aerosols, vehicle emissions, marine aerosols, metallurgy industry. Finally, the application and its limitations of chemical mass balance modeling for PM$_{2.5}$ was discussed.

• Journal of Life Science
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• v.25 no.1
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• pp.53-61
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• 2015

In this study, we tried to separate the photosensitizer that induces apoptosis of leukemia cells (U937) from perilla leaves. Perilla leaves (Perilla frutescens Britt var. japonica Hara) are a popular vegetable in Korea, being rich in vitamins (A and E), GABA, and minerals. Dried perilla leaves were extracted with methanol to separate the photosensitizer by various chromatographic techniques. The structure of the isolated compound (PL9443) was identified by 1D-NMR, 2D-NMR, and FAB-mass spectroscopy. Absorbance of the UV-Vis spectrum was highest at 410 nm and was confirmed by the 330, 410, and 668 nm. PL9443 compound was determined to be pheophorbide, an ethyl ester having a molecular weight of 620. It was identified as a derivative compound of pheophorbide structure when magnesium comes away from a porphyrin ring. Observation of morphological changes in U937 cells following cell death induced by treated PL9443 compound revealed representative phenomena of apoptosis only in light irradiation conditions (apoptotic body, vesicle formation). Results from examining the cytotoxicity of PL9443 substance against U937 cells showed that inhibition rates of the cell growth were 99.9% with the concentration of 0.32 nM PL9443. Also, the caspase-3/7 activity was 99% against U937 cells with the concentration of 0.08 nM of PL9443 substance. The result of the electrophoresis was that a DNA ladder was formed by the PL9443. The PL9443 compound is a promising lead compound as a photosensitizer for photodynamic therapy of cancer.