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        검색결과 2,503

        2321.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acornic powder was extracted with methanol and ethylacetate to obtain a crude acornic compounds. And they were examined concerning their antioxidant activities for linoleic acid. The results were as follows: 1. Hydrogen donating activity for DPPH was higher in 100ppm acornic compound than 100ppm BHT and 100ppm α-tocopherol. 2. When the 100ppm acornic compound was added to linoleic acid, which was heated at 50℃ for 48 hours, antioxidant activities by POV and TBA was higher than that of 100ppm α-tocopherol, but the effect was almost the same as the 100ppm BHT. 3. Antioxiodant activity of acornic compound showed synergistic effect along with malic acid, citric acid, tartaric acid, alanine, arginine, histidine, lysine-HCl, galactose, maltose, glucose and sucrose. 4. Acornic compound inhibited peroxidation of linoleic acid induced by heavy metals.
        4,000원
        2322.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to search for separate and identify of Quercus acutissima CARRUTHERS tannins. Tannins were extracted with methanol and ethylacetate from acorn powder and identified TLC, UV spectrum, HPLC, IR, GC/MS, and 1H NMR. Three spots(Rf 0.94, 0.84 and 0.29) detected on TLC. These spots gave dark blue color fairly on spraying with 0.3% potassium ferricyanid·0.3% ferricchloride reagent, and these tannins identified as gallic acid, caffeic acid and ellagic acid by UV spectrum, HPLC, IR, GC/ MS, and 1H NMR.
        4,000원
        2323.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The syntheses of urocanic acid esters was optimized, starting from p-toluenesulfonic acid salt of this acid and long chain fatty alcohols in the organic solvent and extracting water from it by means of azeotropic Compound. The salts of these urocanic acid esters showed amphoteric properties, but their micellization enhances their rate of hydrolysis leading to the free amine. Nevertheless the long chain gives to the esters themselves an amphoteric character allowing their solubilization in micellar media and in microemulsions the result, yield could enhanced.
        4,000원
        2324.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The hydrolysis kinetics of 2-furyl chalcone derivatives [I]~[V] was investigated by ultraviolet spectrophotometery in 30% dioxane-H2O at 25℃ and the structure of these compounds were ascertained by means of ultraviolet, infrared and NMR spectra. The rate equations which were applied over a wide pH range(pH 1.0~12.0) were obtained. The substituent effects on 2-furyl chalcone derivatives [I]~[V] were studied, and the hydrolysis were facilitated by the electron attrecting groups. On the basis of the rate equation, substituent effect, general base effect and final product. the plausible hydrolysis mechaism was proposed: Below pH 4.0, it was only proportional to concentration of hydronium ion, at pH 4.0~9.0, neutral H2O molecule competitively attacked on the double bond. By contrast, above pH 9.0, it was proportional to concentration of hydroxide ion.
        4,000원
        2325.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1, 2-Isopropylidene glycerol produced by ketalyzation of glycerol with aceton was esterified with long chain fatty acids in the presence of a Mucor miehei lipase to obtain 1, 2-isopropylidene 3-long chain acyl glycerol. To determine optimal conditions for the esterification reaction, esterification was proceeded as a reversible second-order reaction in various parameters that are enzyme<SUB>strate ratio 0.096g</SUB>g at reaction temperatures ranged from 25℃ to 70℃. The order of reaction rate of fatty acids were lauric acid, myristic acid, oleic acid, and stearic acid. The range of their activation energies were from 7.8 to 11.4 (kcal/mol) and that of entropies of activation which have negative values were from 42.8 to 52.5(e.u.).
        4,000원
        2326.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fatty acid, all cis-δ5,11,14-C20:3, in the Gingko nuts oils, was isolated and, purified by urea-adduct method, silver ion silica gel chromatography and HPLC equipped with reversed phase μ-Bondapak C18 column. Its structural elucidation was conducted by IR and 1H-, 13C-NMR technique. The fatty acid composition of seed oils mainly consists of linoleic acid(37.73%), vaccenic acid(18.30%), oleic acid(15.18%), palmitic acid(3.37%), palmitoleic acid(3.37%) and δ5 NMDB fatty acids(8.50%) in which all cis-δ5,11,14-C20:2 predominates.
        4,000원
        2327.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ground Calcium Carbonate, among paper coating pigments, will influence less dispersant demand, less binder demand, increase coating solids from 58% to 70%, which means high speed coating, less shrinkage during drying, less energy consumption, more uniform coverage of fibers. The quality point of view of Ground Calcium Carbonate, brightness, particle size, Particle size distribution, hardness, impurities content are important. More important factors of Ground Calcium Carbonate which influence the paper coating process are dispersion mechanisms and their effects. The study was made to investigate the effect of Ground Calcium Carbonate dispersion by sodium salt of polyacrylate dispersant composition and dispersion condition. Basic tests such as physical, optical and chemical were perfumed, and dispersion effects were investigated by different conditions. The results showed that the type of dispersant affected the dispersion effects, and the Ground Calcium Carbonate has critical dispersant demand.
        4,000원
        2328.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed observe the effect of vegetable oil on the liver of 0.5% cholesterol-fed rats. In this experiment, male rats of Sprague-Dawley strain were used. The rats were divided into 5groups which were fed differently either for 8 weeks: basal diet, 20% sunflower oil diet, 20% soybean oil diet, 20% rapeseed oil diet.,20% coconut oil diet. The total cholesterol, triglyceride level in the liver were showed tendency of increase with increasing of P/S ratios. Bile acid excretion in the fecal increased with increasing of P/S ratios. The value of TBA in the serum and liver were increased in proportion to the amount of polyunsaturated fatty acid. The liver fatty acid of coconut-fed group showed larger variation than fatty acid of the cocount oil. The fat chang of sunflower oil diet in the liver showed the largest change.
        4,000원
        2329.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Anionic polyolic surfactants, alpha-sulfo fatty acids that straight long chain alkyl group has from 12 to 18 hydrocarbon numbers, was synthesized with sulfur trioxide-dioxane complex to good yields. New sodium alpha-sulfo long chain fatty acid monoglyceride were obtained by reaction that the ketalificaticn and esterification of glycerol, acetone and alpha-sulfo long chain fatty acid and hydrolysis respectively. These reaction products separated by column chromatography and their Rf values(Rf×100) were 19, 21, 24 and 26 respectively. These compounds were identified by infrared spectroscopy and 1H NMR spectroscopy.
        4,000원
        2330.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transesterification reaction between dimethyl phthalate and ethylene glycol was kinetically investigated in the presense of various metal nitrate catalysts at 170℃. The reaction rates measured by the amount of distilled methanol from the reaction vessel. The transesterification reaction was carried out under the first order conditions respect to the concentration of dimethyl phthalate and catalyst, respectively. The over all order was 2nd. By Arrhenius plot, the activation energy was calculated as 17.4kcal/mole and 17.2kcal/mole on the transesterification reaction with zinc nitrate and lead nitrate, respectively. Apparent rate constant, k' was appeared linear about concentration of catalyst.
        4,000원
        2331.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recent studies on enzyme reactions in organic solvents are revived. The reactions are classified into three categories: heterogeneous, biphasic and homogeneous systems. The following subjects are described and discussed about the heterogeneous system. 1) The maximal expression of enzyme activity in organic solvents in terms of water content, hydration of enzyme, and equilibriun of water between enzyme and substrate solution. 2) Solvent effect on the catalytic power of enzyme. 3) Thermostability and thermoreactivity. 4) Applications of the enzyme reactions to synthetic chemistry.
        4,600원
        2332.
        1993.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The possibilities for HPLC analysis of lipids have been revolutionised by the availability of evaporative light-scattering detectors, with which the response is independent of the nature of the mobile phase and does not depend On the presence of specific chromophores in the lipids. It was thus possible to develop an HPLC procedure, involving ternary gradient elution, for separating all the lipid classes in animal tissues in a single step. Although reversed-phase HPLC has been widely used for the analysis of molecular species of lipids, sliver ion chromatography can be a valuable alternative. For example, a stable silver ion column for HPLC was developed which permitted resolution of molecular species of triacylglycerols, even from such complex samples as fish oils, again With light-scattering detection and gradient elution. The capacity for HPLC resolution of diastereomeric diacyl-sn-glycerol derivatives, prepared from triacylglycerols. has lead to a new simple method for stereospecific analysis of the latter.
        4,000원
        2333.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed evaluate the change of fat content according to cooking methods of ground beef. The results are summarized as follows. 1. The fat content of ground beef is the lowest in boiling cooking method. 2. The fatty-acids composition of ground beef is mainly palmitic and oleic acids. The fatty acids hardly change according to cooking methods. 3. P/S ratio is inclined to increase a bit after cooking than pre-cooking. From all the results obtained in this study it can be conclude that fat content is the lowest in boiling and microwaving cooking methods and fatty acid composition is mainly palmitic and oleic acids.
        4,000원
        2334.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Methyl linoleate의 자동산화와 인지질에 작용하는 lipoxygenase의 활성에 미치는 탄닌산과 알파토코페롤의 영향을 HPLC로 조사하였다. 반응혼합물은 methyl linoleate 70mM, 라디칼 생성체 AMVN와 탄닌산 및 알파토코페롤 각각 0.7mM를 함유하였다. Hydroperxide 생성량을 측정하여 탄닌산과 알파토코페롤이 상당히 좋은 항상화제임을 알았고, 인지질 1μm에 탄닌산과 알파토코페롤을 각각1μm 함유한 혼합물에 효소를 첨가하여 활성 억제효과를 측정하여, 탄닌산과 알파토코페롤이 좋은 효소 활성 억제작용을 하고 있음을 알았다.
        4,000원
        2335.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The standardized activated sludge for the biodegradation test of anion surfactants has been produced from the collected microorganisms in the soil and the wastewaters treatment plant. The activated sludge was kept under control of the pH, dissolved oxygen, microorganisms and inoculated the basal medium flasks with LAS and LAS mixed with heavy metals [Cd(II), Cu(II), Zn(II)]. Based of results, the inhibition effect(%) of heavy metals in LAS biodegradation were 1. All 1% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 0.1mg/l, respectively 2. All 1~10% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 1mg/l, respectively 3. All 10~40% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 10mg/l, respectively 4. All 30~65% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 100mg/l, respectively And toxicity order of heavy metals to the microorganisms in LAS biodegradation were Cd〉Cu〉Zn in low concentration(0.1~1mg/l)and Cd〉Zn〉Cu in high concentration(10~100mg/l).
        4,000원
        2336.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A microorganism, isolated from soil and designated Pseudomonas sp13, produced two kinds of rhamnolipid in the medium containing glucose as carbon source. There were both rhamnolipid contain L-rhamnose and β-hydroxydecanoic acid. Coumpound A and B elucted chloroform-methanol mixed solution of silicic acid column chromatography and recrystallized from a mixture of ether and n-hexane. Studies on the structure of these products reveled that compound A is L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid and compound B is L-rhamnopyranosyl-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoic acid.
        4,000원
        2337.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Levels of total lipids in the seeds of three species of the Pinaceae family were determined and their fatty acid compositions were also analyzed by a gas-chromatograph equipped with a capillary column coated with Carbowax 20M. The results are summarized as follows: Lipid contents of the seeds amounted to 56.9% in P. koraiensis, 29.9% in P. thunbergii, and 21.2% in P. rigida. In all lipids 19~20 fatty acid were detected and, surprisingly, fatty acids having δ5-non-methylene interrupted conjugate double bond such as δ5, 9-C18:2,δ5, 9, 12-C18:3 and δ5, 11, 14-C20:3 occurred in appreciable amounts. In the lipids of P. koraiensis, the main component was C18:2Ω6(45.0%), followed by C18:1Ω 9(26.9%) and δ5, 9, 12-C18:3(14.6%), and then δ5, 9-C18:2(2.2%) and δ5, 11, 14-C20:3 were also present. Levels of saturated fatty acid such as C16:0 and C18:0 were as low as 7.5%. The seed oil of P. thunbergii predominantly comprised C18:2Ω6(45.2%), and was then occupied by equal amounts δ5, 9, 12-C18:3(18.1%) and C18:1Ω9(18.1%). Its δ5, 11, 14-C20:3(5.8%) level was the highest in the samples tested. δ5, 9-C18:2(2.8%) was also detected with other minor components. In the oils from the seeds of P. rigida, C18:2Ω6 was present as a main component, accompanied by C18:1Ω9(21.6%) and δ5, 9, 12-C18:3(20.3%). The latter showed higher level than in any other samples. A minor component corresponding to δ5, 9, 12, 15-C18:4(not confirmed by GC-Mass) occurred in P. thunbergii and P. rigida.
        4,000원
        2338.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at 120~170℃ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.
        4,000원
        2339.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was separated and identified prostaglandin from garlic by TLC, HPLC, and Gc-Mass. In this experiment aimed at researching the effects of garic on body weight, and serum lipid, protein and glucose in male rats. The male rats applied in this work were 42 of Sprague-Dawley strain. In addition to basal diet, the worker administrated 4 groups of the experimental rats solutions which were 0.2 and 0.4ml of raw garlic juice, and of etanol garlic extract with together 2.5% cholesterol solution solved by corn oil for 8 weeks respectively. These results were as follows. 1. Separated and identified of Prostaglandin from garlic. 2. The growth rate of body weight and food efficiency ratio(FER) appeared to be more increased in the experimental groups administrated ethanol garlic extract than raw garlic juice. 3. The content of serum total cholesterol apperaded to be decreased in the experimental group administrated 0.4ml of ethanol garlic extract. 4. The level of serum HDL-cholesterol had a tendency to be more increased in all the experimental groups administrated garlic than control group. 5. The level of serum glucose appeared to be decreased in all the experimental groups administrated garlic, particularly ethanol garlic extract.
        4,500원
        2340.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kinetics of the hydrolysis of indolylacrylophenone derivatives(IA) was investigated by ultraviolet spectrophotometry in 30% dioxane-H2O at 25℃ Rate equations were obtained over a wide pH range. On the basis of rate equation, general base catalysis and Hammett's plot, the mechanism of hydrolysis to the (IA) were proposed: Below pH 3.0, the hydrolysis of (IA) was proportional to hydronium ion concentration, between pH 4.0~9.0 neutral water molecule and hydroxide ion were added to carbon-carbon double bond and over pH 10.0 hydrolysis of (IA) was proportional to hydroxide ion concentration.
        4,000원