• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.04a
• /
• pp.229-229
• /
• 1994

선택성이 높고 뛰어난 약효를 지닌 항 바이러스제의 개발은 신약개발의 중요한 영역중에 하나이다. 현재 AIDS 치료제로 사용되고 AZT를 비롯하여 항virus 효과를 나타내는 약물의 대부분은 구조적으로 nucleoside계에 속하는 화합물로서 수 많은 약리학적 연구 및 합성 화학적 연구가 이루어져 왔다. 특히 합성 화학적 측면에서 이들 화합물의 합성은 크게 두가지로 나누어지는데 그것은 sugar 부위의 변형을 통한 방법과 염기 부위의 변형을 통한 방법에 의해 새로운 항 바이러스제를 개발하는 것이다. 최근의 연구 동향에 있어서 주목할 만한 변화의 하나는 sugar 부위의 구조적 변형을 시도하는데 있어서 종래의 5원환 형태에서 환이 개열된 형태의 acyclic nucleoside에 대한 연구가 이루어져 좋은 효과를 거두고 인다는 사실이다. Acyclovir, Ganciclovir등 의 개발이 그것이다. 본 연구에서는 종래의 acyclic nucleoside가 ribose sugar의 2'번 및 3'번 탄소를 제거한 acyclic ether 형태로 되어있는 것과는 다르게 ether 부위의 산소를 탄소 치환한 carbo-acyclic nucleoside를 합성하고자 하였다. Acyclic nucleoside를 합성하고자 하였다. Acyclic nucleoside의 side chain의 conformation이 항 바이러스 작용을 나타내는데 필수 불가결한 점을 감안할때, carbo-acyclic nucleoside계 화합물은 보다 다양하게 변형될 수 있는 장점을 가지고 있다. 이러한 관점에서 side chain의 2'번 및 3'번 탄소는 side chain의 conformation을 좌우하는 결정적 요인으로 작용할 것으로 판단된다. 따라서 본 연구에서는 이들 탄소를 중심으로한 분자수식을 시도하기로 하고 bioisosterism을 이용하여 3'위치의 수소를 fluoride로 치환한 화합물을 설계하여 합성을 시도하였다.silyl group-5'-무치환 화합물을 tosyl, azido화 한다음 desilylation하여 얻었다. 목적하는(1) 화합물의 diasteromer 인 2',3'-dihydroxy-5'-무치환 유도체(3)는 (4)화합물 합성시 얻은 hemiactal을 key intermediate로 하여 TsNHNH$_2$, NaB(CN)H$_3$ 및 NaOAc로 처리하므로서 얻을수 있었다. 이들 화합물들의 각종 DNA 및 RNA virus에 대한 항 바이러스작용을 검토한 결과 현저한 항 바이러스 작용을 나타내지 않았다.분화유도 활성을 나타내어 항종양제로의 개발에 많은 흥미가 기대된다.기대된다.oxylic acid (compound 10)를 합성하였다.10^{－7}$ M)에 의한 단백인산화에 대하여는 더 미약한 억제-효과를 나타내었다. 이상의 결과는 PDE-1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인 인체유해 중금속이온인 Hg(II), Cd(II)등이 NaCl같은 염화물이 함유된 시료용액에 공해이온으로 존재할 경우 흡착에 의한 제거가 가능하다. 한편 이같은 중금속이온의 흡착실험은 특히 해수중의 금속이온의 회수연구에도

• Clean Technology
• /
• v.26 no.4
• /
• pp.263-269
• /
• 2020

Zeolite was synthesized hydrothermally using the water-treatment sludge, and the effects of various synthesis parameters like reaction temperature, reaction time, and Na2O/SiO2 molar ratio on the crystallization of zeolite were investigated. Crystal structure, physical property, and thermal stability of zeolite crystals were characterized by X-ray powder diffraction, FTIR spectroscopy, BET nitrogen adsorption, and TGA measurements. The removal efficiencies of nitrogen in ammonia, heavy metal ions, and TOC were calculated to evaluate zeolite's adsorption capacity. The primary chemical composition of water-treatment sludge was 28.79% Al2O3 and 27.06% SiO2. The zeolites were synthesized by merely employing the water-treatment sludge as silica and alumina sources without additional chemicals. Zeolite crystals synthesized through the water-treatment sludge were confirmed as an A-type zeolite structure. Zeolite A had the highest crystallinity obtained from a gel with the molar composition 2.1Na2O-Al2O3-1.6SiO2-65H2O after 5 h at a temperature of 90 ℃. The specific surface area of zeolite obtained was 55 ㎡ g-1, which was higher than commercial zeolite A. The removal efficiency of nitrogen in ammonia was 68% after 3 h of reaction time, while the removal efficiencies of Pb2+ and Cd2+ ions were 99.1% and 99.3%, respectively. These results indicate active ion exchange between Pb2+ or Cd2+ ion and Na+ ion in the zeolite framework. The adsorption experiments on the different zeolite addition conditions were performed for 3 h with 300 ppm humic acid. Based on the results, TOC's highest efficiency was 83% when 5 g of zeolite was added.

• Journal of Environmental Science International
• /
• v.23 no.5
• /
• pp.743-753
• /
• 2014

The number concentrations and the water soluble ionic concentrations of $PM_{2.5}$ have measured at Gosan site in Jeju, Korea, from March 2010 to December 2010, to clarify their characteristics. $PM_{2.5}$ number concentrations vary from 22.57 to $975.65particles/cm^3$ with an average value of $240.41particles/cm^3$, which have been recorded evidently high in spring season as compared with those in other season. And the concentrations in small size ranges are greatly higher than those in large size ranges, so the number concentration in the size range $0.25{\sim}0.45{\mu}m$ has more than 94% of the total number concentration of $PM_{2.5}$. The major ionic components in $PM_{2.5}$ are $SO{_4}^{2-}$, $NH_4{^+}$ and $NO_3{^-}$, which are mainly originated from anthropogenic sources, on the other hand, the concentrations of $Cl^-$, $K^+$, $Ca^{2+}$ and $Mg^{2+}$ are recorded relatively lower levels. The concentrations of the major ionic components are very high in spring season, but the concentration levels of the other components are recorded significantly high in winter season. On the other hand, in summer season, the lowest concentration levels are observed for overall components as well as the sum of them. The concentration ratios of nss-$SO{_4}^{2-}/SO{_4}^{2-}$ and nss-$Ca^{2+}/Ca^{2+}$ are 98.1% and 88.9%. And the concentration ratio of $SO{_4}^{2-}/NO_3{^-}$(3.64) is greatly higher than the value in urban area due to no large $NO_x$ emission sources in the measurement. In addition, the correlation and the factor analysis for the number and the ionic concentrations of $PM_{2.5}$ are performed to identify their sources. From the Pearson correlation analysis and the factor analysis, it can be suggested that the smaller parts(< $0.5{\mu}m$) of $PM_{2.5}$ is contributed by anthropogenic sources, but the sources of the remaining larger parts of $PM_{2.5}$ are not able to be specified sources in this study.

• Microbiology and Biotechnology Letters
• /
• v.30 no.2
• /
• pp.142-150
• /
• 2002

Streptomyces polychromogenes IFO 13072 was used as a strain producing cholesterol oxidase(EC 1.1.3.6). The conditions of cholesterol oxidase production were investigated. The optimum composition of medium for production of the enzyme was 1% dextrin, 0.5% casamino acid, 0.1% $KH_2$PO$_4$, 0.5% $NaNO_3$ and 0.05% $MgSO_4$(pH 7.3). The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 23.2%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated about 52,000 daltons. The optimum pH and temperature of the cholesterol oxidase were pH 7.0 and $37^{\circ}C$, respectively. The enzyme was stable in the range of pH 6.0~7.0 and $25^{\circ}C$. The cholesterol oxidase activity was strongly inhibited by metal ions such as $Hg^{2＋}$ and $Fe^{2＋}$ and inhibitors such as dithiothreitol, mercaptoethanol and isonicotinic acid. The Michaelis constant(Km) for the cholesterol was found to be 25 mM by Lineweaver-Burk plot analysis.

• The Korean Journal of Pesticide Science
• /
• v.18 no.3
• /
• pp.141-147
• /
• 2014

Fenpyroximate is acaricide of pyrazole group. This acaricide have already been permitted for herb cultivation. This experiment was conducted to establish a determination method for fenpyroximate residue in herbal medicines using HPLC-PDA and HPLC-MS/MS. Fenpyroximate residue was extracted with acetone from samples of herbal which Liquorice Root (Glycyrrhiza uralensis) and Safflower Seed (Carthamus tinctorius Linne). The extract was diluted with saturated saline water and dichloromethane liquid-liquid partition (extraction) was followed to recover fenpyroximate from the aqueous phase. Amino propyl ($NH_2$) and florisil column chromatography was additionally employed for final clean up of the extract. The fenpyroximate was quantitated by HPLC-PDA and HPLC-MS/MS. The herbals were fortified with fenpyroximate at 2 or 3 levels per crop. Mean recovery ratio were ranged from 72.0 to 106.4%. The coefficients of variation were ranged from 0.2 to 4.4. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fenpyroximate in herbal medicines.

• Korean Journal of Poultry Science
• /
• v.31 no.4
• /
• pp.229-235
• /
• 2004

A study was conducted to examine the effect of dietary supplementation of multiple probiotics (EM) on growth performance, blood cholesterol, intestinal micro flora, and fecal gas emission in broiler chicks. A total of 450 one day old male broiler chicks (Ross $\times$ Ross) were divided into six treatments with five replications in each treatment for five weeks. Treatments were factorially designed with two levels of diet containing probiotics (DW; 0, $0.2\%$) and three levels of drinking water containing probiotics (DW; 0, 0.01, $0.1\%$). Basal diets contained $21.5\%$ CP and 3,100 kcal/kg ME for starting and $19\%$ CP and 3,100 kcal/kg ME for finishing period. Weight gain, feed intake, and feed conversions of birds fed with probiotics were not significantly different between Ds. Total cholesterol and triglyceride levels were significantly lower (P<0.05) in birds fed with DW $0.01\%$ or $0.1\%$ compared with no probiotics group, but there was no significant difference between D treatments. The number of E. coli, Salmonella and Lactobacillus in the ileum and cecum of the birds fed multiple probiotics were not significantly different from those of no probiotic groups. There were no significant differences in the $CO_2$ gas emissions of fecal between birds fed with Ds or among birds fed with DW. However, $NH_3$ gas emissions of DW $0.1\%$ were significantly lower (P<0.05) than DW $0\%$. In the results of this study, supplementation of probiotics tended to decrease the serum cholesterol and triglyceride compared to those of control groups and reduction of fecal $NH_3$ gas emission.

• Journal of Korean Society for Atmospheric Environment
• /
• v.31 no.1
• /
• pp.28-40
• /
• 2015

To investigate the seasonal variations of carbonaceous aerosol in Daejeon, OC (organic carbon), EC (elemental carbon) and WSOC (water soluble organic carbon) in $PM_{2.5}$ samples collected from March 2012 to February 2013 were analyzed. $PM_{2.5}$ concentrations were estimated by the sum of organic matter ($1.6{\times}OC$), EC, water-soluble ions ($Na^+$, $NH_4{^{+}}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $SO_4{^{2-}}$, $NO_3{^{-}}$). The estimated $PM_{2.5}$ concentrations were relatively higher in winter ($29.50{\pm}12.04{\mu}g/m^3$) than those in summer ($13.72{\pm}6.92{\mu}g/m^3$). Carbonaceous aerosol ($1.6{\times}OC+EC$) was a significant portion (34~47%) of $PM_{2.5}$ in all season. The seasonally averaged OC and WSOC concentrations were relatively higher in winter ($6.57{\times}3.48{\mu}gC/m^3$ and $4.07{\pm}2.53{\mu}gC/m^3$ respectively), than those in summer ($3.07{\pm}0.8{\mu}gC/m^3$, $1.77{\pm}0.68{\mu}gC/m^3$, respectively). OC was correlated well with WSOC in all season, indicating that they have similar emission sources or formation processes. In summer, both OC and WSOC were weakly correlated with EC and also poorly correlated with a well-known biomass burning tracer, levoglucosan, while WSOC is highly correlated with SOC (secondary organic carbon) and $O_3$. The results suggest that carbonaceous aerosol in summer was highly influenced by secondary formation rather than primary emissions. In contrast, both OC and WSOC in winter were strongly correlated with EC and levoglucosan, indicating that carbonaceous aerosol in winter was closely related to primary source such as biomass burning. The contribution of biomass burning to $PM_{2.5}$ OC and EC, which was estimated using the levoglucosan to OC and EC ratios of potential biomass burning sources, was about $70{\pm}15%$ and $31{\pm}10%$, respectively, in winter. Results from this study clearly show that $PM_{2.5}$ OC has seasonally different chemical characteristics and origins.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.1
• /
• pp.12-24
• /
• 1990

Two trypsin-like enzymes, designated trypsin A and 3, purified from the intestine of menhaden by $(NH_4)_2SO_4$ fractionation, Benzamidine-Sepharose 6B affinity chromatography, DEAE-Sephacel ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The two trypsins were subjected to compare the enzymatic properties of the trypsin-like enzymes from the other dark fleshed fishes. Both trypsins catalysed the hydrolysis of N$\alpha$-benzoyl-DL-arginine-p-nitroanilide and they were remarkably inhibited by several well known trypsin-inhibitors, tosyllysyl chloromethyl ketone, soybean trypsin inhibitor, be-nzamidine, leupeptin and antipain, etc. Therefore, it was ascertained that the two enzymes are serine-type trypsins. The molecular weights of these enzymes were about 25,000 and 26,200, respectively, ;Is determined by SDS-PAG electrophoresis and by Sephadex G-100 gel filtration, and the molecular weights of these two enzymes are somewhat fewer than those from the other dark fleshed fishes. Both enzymes had less basic amino acids such as arginine and Iysine, whereas they had slightly high contents of neutral amino acids, glycine, alanine and tryptophane. The enzymes showed a pH optimum of $8\~11$ at $60^{\circ}C$ against the $N\alpha$-benzoyl-DL-argi-nine-p-nitroanilide substrate and they were quite unstable above $40^{\circ}C$ and under the atidic pH region. The Km constant of the two enzymes against the $N\alpha$-benzoyl-DL-arginine-p-nitroanilide was $1.4\times10^{-4}M$ for trypsin A and $4.3\times10^{-5}M$ for trypsin B, respectively.

• Korean Journal of Microbiology
• /
• v.40 no.3
• /
• pp.199-204
• /
• 2004

The parathion hydrolase (OPH) produced by Pseudomonas rhodesiae H5 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Parathion hydrolase from crude extracts of P. rhodesiae H5 has two components designated as OPH $I_1$ and OPH $I_2$, Optimum pH and temperature of OPH $I_1$and OPH $I_2$ were pH 7.2 and $30^{\circ}C$, and pH 7.6 and $37^{\circ}C$, respectively. The activation energy of OPH $I_1$ for the hydrolysis of parathion was 3.01 ㎉/I, II, III in the temperature range of $4^{\circ}C$ to $30^{\circ}C$, and Michaelis constant ($K_m$) for parathion was 69.2 ${\mu}M$. The activation energy of OPH $I_2$ for the hydrolysis of parathion was 4.07㎉/㏖ in the temperature range of $4^{\circ}C$ to $37^{\circ}C$, and Michaelis constant for parathion was 150.9${\mu}M$. Furthermore OPH $I_1$ was completely inhibited by 1 mM $Ca^2+$, $Cu^2+$, $Mg^2+$, $Ni^2+$, but OPH $I_2$ was less inhibited than OPH $I_1$ by the metals used in this study.

• Korean Journal of Ecology and Environment
• /
• v.42 no.3
• /
• pp.350-363
• /
• 2009

Inter- and intra-specific differences in removal activities, filtering rates (FR) and production of feces-and pseudo-feces (PF) between a native freshwater bivalve in Korea, Anodonta woodiana Lea and Unio douglasiae Griffith et Pidgeon, were compared using a continuous removal of organic matters (CROM) system. The CROM system comprised five steps; input of polluted water, control of water flow, mussel treatment, analysis of water quality and discharge of clean water. The study was designed to compare the removal activity of organic matters between A. woodiana and U. douglasiae, and the intra-specific differences between density and length in A. woordiana. Results clearly indicate that two kinds of mussels had obvious removal activities of seston in the eutrophic reservoir. First, if both are similar in shell length, there were no significant inter-specific differences in removal activity between A. woordiana and U. douglasiae (P>0.5), but FRs of U. douglasiae was relatively high due to low ash-fee dry weight. Second, if both are same in animal density, the smaller mussels (1$\sim$2 years old) showed a higher filtering rate and production of feces- and pseudo-feces and less release of ammonium than the larger mussels. Third, if both are same in biomass, FRs and PF of mussels were higher in the low-density tank than the high-density tank, While the Concentration of $NH_4$-N and $PO_4$-P released WRS similar to each other (P>0.5). Therefore, these results suggest that CROM system using a young bivalve A. woordiana can be applied to control the nuisance seston in eutrophic lake system, if a relevant species and density were selected. Additional pilot tests to optimize the age and density of domestic bivalves were needed for the generalization of CROM operation.