• Journal of the Korean Chemical Society
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• v.25 no.5
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• pp.306-310
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• 1981

Induced circular dichroism spectra of racemic cobalt(III) complexes for $[Co(en)_3]^{3+},\;[Co(tn_)3]^{3+},\;cis-[Co(NH_3)(en)_2]^{3+},\;[Co({\beta}-ala)(en)2_]^{2+},\;[Co(gly)(en)_2]^{2+}\;and\;[Co(acac)(en)_2]^{2+}$ were measured when they were dissolved in aqueous d-tartrate2- solution at room temperature. Only a single negative CD spectrum was observed for all the complexes above in visible region(400∼500nm). It was interpreted that these CD bands were attributed to the difference in interaction between ${\Lambda}$-and ${\Delta}$-enantiomers with d-tartrate$^{2-}$. Namely, when d-tartrate$^{2-}$ was added to ${\Lambda}$-enantiomer and ${\Delta}$-enantiomer, it caused ${\Lambda}$-enantiomer to change greatly and ${\Delta}$-enantiomer to change only slightly; combined the results proved induced circular dichroism. The enantiomer for which the eluent has a stronger affinity should be eluted faster in ion-exchange column chromatography. It is possible to predict the elution order of chromatography from the sign of the induced CD if stronger interaction of chiral anion with the complex leads to greater change in the natural CD spectrum of the complex. The elution order was in complete agreement with the prediction from the sign of the induced CD spectrum for all the measured complexes.

• Analytical Science and Technology
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• v.14 no.2
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• pp.95-102
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• 2001

A comprehensive analytical method of endocrine disruptors[i.e., nonylphenol(NP), octylphenol(OP), bis(2-ethylhexyl) phthalate(BEHP)] in meat or pork samples was developed. The method employed closed culture tube extraction with dichloromethane and solvent exchange to iso-hexane and SPE(2g) aminopropyl column, followed by determination on gas chromatography linked to mass spectrometry(GC/MS) operated in the single ion monitering(SIM) mode. For the multipoint recovery of nonylphenol, octylphenol and bis(2-ethlhexyl) phthalate OP, NP were showen good recoveries in $0.125-1.25{\mu}g/g$ range of concentration, and BEHP more good recoveries in $0.0125-12.5{\mu}g/g$ wide range of concentration. The present method was applied to beef or pork samples of mart and butcher in Cheonju city and near Cheonju. The range of concentrations was respectively, $0.06-0.24{\mu}g/g$ in nonylphenol(NP) and $0.36-2.35{\mu}g/g$ in bis(2-ethylhexyl) phthalate(BEHP), but octylphenol(OP) was not dected in any samples. This method provides a powerful analytical tool to investigate a wide range of endocrine disruptors in biological samples of limited quantity.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.100-106
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• 1999

The polysaccharides, intracellular and extracellular, extracted from the liquid culture of the Agrocybe cylindracea were purified and characterized. The mycellial cellular productivity of Agrocybe cylindracea was proved to be almost 2 folds in the shaking culture compared to the standing culture. These polysaccharides were purified by the DEAE-cellulose ion exchange chromatography and the Sepharose 2B size exclusive gel filteration. The two purified fractions of extracellular polysaccharides, ACEPDG and ACEPAG, contained 75.8% and 65.4% total sugar respectively. The total sugar content of ACIPDG and ACIPAG, the two purified fractions of intracellular polysaccharides, were 89.2% and 54.2% respectively. The molecular weights range of all the substances were estimated to be above 100,000, from 300KDa of ACEPDG to 600 KDa of ACIPAG. The results of sugar analysis by HPLC showed that the sugar part of ACEPDG was consisted of glucose and inositol. The ACIPDG, ACEPAG and ACIPAG contained three kinds of monosaccharides, glucose, fructose and inositol.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.457-464
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• 2006

Three extracellular proteases (Vpr, peptidase T, and subtilisin) were identified from the culture supernatant of Bacillus subtilis KCTC 3014. All the proteins were partially purified as a mature form by using a DEAE-cellulose ion-exchange column chromatography. Their activities were determined by using zymography and densitometry. The relative molecular masses of Vpr and peptidase T (PepT) were determined to be 68 and 48 kDa by SDS-PAGE and zymography, respectively. However, subtilisin formed a 'binding mode' at the top of the separating gel. After denaturation by boiling at $100^{\circ}C$ for 5 min, its molecular mass was determined to be 29 kDa, whereas its activity was lost. The optimal pH of Vpr, PepT, and subtilisin were 9.0, 6.0-7.0, and 7.0-8.0, respectively. The optimal temperature of Vpr, PepT, and subtilisin was 40, 50, and $40^{\circ}C$, respectively. Inhibitor test revealed that Vpr and subtilisin were serine proteases and that PepT was a metalloprotease. Interestingly, we found that Vpr showed no enzyme activity on a 2DE zymogram gel. Three genes, vpr, pepT, and apr (encoding subtilisin protein), were cloned and their nucleotide and deduced amino acid sequences were determined.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.159-172
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• 1993

Collagenase existed in the internal organs of filefish Novoden modestrus was isolated with ammonium sulfate and was purified by ion exchange column chromatography with DEAE-Sephadex A-50 and gel filtration with Sephadex G-150. The activity of the purified enzyme was increased 92.4 folds than that of the crude one and the yield of the purified one was $10.9\%$. The optimum conditions showing the maximum activity of the crude enzyme to digest insoluble collagen(Type I) were $55^{\circ}C$ and pH 8.0, while those showing the maximum activity of the purified one were $55^{\circ}C$ and pH 7.75. However, the use of the crude enzyme for skinning of filefish was more profitable because the yield was 800 folds higher than that of the purified one and the cost was also able to economy. When hydrolysis for skinning of filefish was conducted with $0.3\%$(w/w) crude collagenase at $50^{\circ}C$ and pH 8.0 for 3hrs, there was some problem to cause a damage on muscle of the fish by heat. To solve such problem for the skinning, the hydrolysis at $18^{\circ}C$ for 4hrs with $0.3\%$ (w/w) crude enzyme after pretreated with 0.5M acetic acid for 10 min provided a good result for skinning of filefish.

• IMMUNE NETWORK
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• v.4 no.2
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• pp.94-99
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• 2004

Background: We previously reported that ginsan, a polysaccharide extracted from Panax ginseng had an immunostimulatory activity such as mitogenic activity, activation of macrophages and killer cells, and production of a variety of cytokines which resulted in antitumor and antiseptic effects. We further purified $\alpha$-(1$\longrightarrow$6)-glucan and $\beta$-(2$\longrightarrow$6)-fructan from the ginsan with size exclusion and ion-exchange column chromatography successively. In this study, we performed the structure-based activity of ginsan by comparison with known polysacchrides such as $\beta$-glucan, curdlan, laminarin, levan, dextran, lentinan and OK-432. Methods: To investigate the immunostimulatory activity of several polysaccharide compounds, we investigated the stimulation of lymphocytes proliferation, the generation of activated killer cells and the secretion of nitrites from activated macrophages. Results: Of polysaccharides tested, curdlan and ginsan stimulated lymphocyte proliferation, suggesting that the molecular weight and composition of polysaccharide are dependent on the mitogenic activity. The production of nitric oxide was significantly increased in curdlan, levan, ginsan and its fraction, indicating that fructan has also capacity to activate macrophages and may devote to kill pathogens. In addition, the activation of macrophages was seemed to be independent of molecular weight of polysaccharide. The generation of AK cells was exhibited in order of curdlan, OK-432> F1, ginsan, F3> levan> etc. The AK activity may be dependent on molecular weight and composition of polysaccharides. Conclusion: Unfortunately, purified polysaccharide from ginsan were less active on immunostimulatory activity than mixed compounds of polysaccharides. From the viewpoint of structure and activity relationships, we found several characteristic features.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.89-119
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• 2004

This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

• Applied Biological Chemistry
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• v.13 no.2
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• pp.111-129
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• 1970

As a series of studies on the nucleic acids and their related substances 210 samples were collected from 76 places such as farm soil, compost of heap, nuruk and meju to obtain microbial strains which produce 5'-phosphodiesterase. From these samples total of 758 strains were isolated by the use of dilution pour plate method. For all isolated strains primary screening of the productivity of RNA depolymerase was performed and useful strains with regard to 5'-phosphodiesterase productivities were identified. For these useful strains optimum condition, the effect of various compounds on the activity of 5'-phosphodiesterase, and the optimum condition for enzyme reaction were discussed. The quantitative of 5'-mononucleotides produced by the action of 5'-phosphodiesterase was performed using anion-exchange column chromatography and their identified was done by paper chromatography, thinlayer chromatography, ultra violet spectrophotometry, and characteristic color reaction using carbazole and schiff's reagent. (1) Penicillium citreo-viride PO 2-11 and Streptomyces aureus SOA 4-21 from soil were identified as a potent 5'-phosphodiesterase producing strains. (2) Optimum culture conditions for Penicillium citreo-viride PO 2-11 strain isolated were found to be pH 5.0 and $30^{\circ}C$, and the optimum conditions for enzyme action of 5'-phosphodiesterase were pH 4.2 and $60^{\circ}C$. Best carbon source for the production of 5'-phosphodiesterase was found to be sucrose and ammonium nitrate for nitrogen source. Addition of 0.01% corn steep liquor or yeast extract exhibited 20% increase in the amount of 5'-phosphodiesterase production compared to the control. 5'-phosphodiesterase produced by this strain was activated by $Mg^{++},\;Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by EDTA, citrate, $Cu^{++},\;CO^{++}$. 5'-phosphodiesterase produced 5'-mononucleotide from RNA at a rate of 65.81%, and among the 5'-mononucleotides accumulated 5'-GMP only was found to have flavorous and the strain was also found lack of 5'-AMP deaminase. Productivity of flavorous 5'-GMP was found to be 186.7mg per gram of RNA. (3) Optimum culture canditions for the isolated Streptomyces aureus SOA 4-21 strain were pH 7.0 and $28^{\circ}C$, and the optimum conditions for the action of 5'-phosphodiesterase were pH 7.3 and $50^{\circ}C$. The best carbon source for 5'-phosphodiesterase production was found to be glucose and that of nitrogen was asparagine. Addition of 0.01% yeast extract exhibited increased productivity of 5'-phosphodiesterase by 40% compared to the non-added control. 5'-phosphodiesterase produced by this strain was activated by $Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by citrate, EDTA, $Cu^{++}$. It was also found that the strain produce 5'-AMP deaminase in addition to 5'-phosphodiesterase. For this reason although decomposition rate was 63.58% the accumulation of 5'-AMP, 5'-CMP, 5'-GMP and 5'-UMP occurred by the breakdown of RNA. In the course of these reaction 5'-AMP deaminase converted 60% of 5'-AMP thus produced into 5'-IMP and flavorous 5'-mono nucleotide production was significantly increased by this strain over the above mentioned one. Production rates were found to be 171.8mg per grain of RNA for 5'-IMP and 148.2mg per gram of RNA for 5'-GMP, respectively.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.41-48
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• 2004

Cyclodextrin glucanotransferase (CGTase) of Bacillus sp. isolated from soil was purified and its enzymological characteristics were investigated. It was found that the production of CGTase reached to the maximum when the strain was cultured in the broth containing 0.1 % albumin, 2% $NH_4Cl$, 2% soluble starch and 0.2% $NH_2PO_4$ for 72 hrs at $37^{\circ}C$. The purity of CGTase was increased by 9.7 folds through purification procedures by the following column chromatography DEAE-cellulose ion exchange chromatography and Sephadex G-100, G-150 gel filtration and its specific activity was 528.0 unit/mg. The optimum pH and temperature for the CGTase activity were 8.0 and $80^{\circ}C$, respectively. The enzyme was stable in pH $8.0{\sim}11.0$ at $60{\sim}80^{\circ}C$. The activity of purified enzyme was inhibited by $Pb^{2+},\;Hg^{2+}$ and $Zn^{2+}$. When CGTase was treated with each 20.5 unit, 41 unit, 205 unit and 410 unit to investigate the transglucosylation to stevioside by purified cyclodextrin glucanotransferase, transglucosylation rate to stevioside was 74.9%, 75.7%, 68.7% and 57.9%. Brown effect was observed above the concentration amounting to 205 unit of our CGTase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.684-688
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• 2003

The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.