• 제목/요약/키워드: compound-K

검색결과 8,269건 처리시간 0.04초

Pancreatic lipase Inhibitory Compound from Apis mellifera venome

  • Kim, Jun-Ran;Kim, Shin-Duk
    • International Journal of Industrial Entomology and Biomaterials
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    • 제16권2호
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    • pp.57-59
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    • 2008
  • While searching for pancreatic lipase inhibitors, the active compound was found in a methanol extract of Apis mellifera venome. The active compound was isolated by Diaion HP-20 column chromatography, thin layer chromatography and HPLC. The active compound is stable to the extreme pH and heat. There is no loss of activity both in acidic and alkaline solution in the pH range of 2 to 11 by heating for 15 minutes at $90^{\circ}C$. The rf value of the compound was 0.51 at TLC with butanol : methanol: water (4:1:2) solvent system. The molecular weight of the compound was determined to be 293 by EI-MS.

TMA-물계 포접화합물의 냉각특성과 과냉각 개선에 대한 연구 (A Study on the Cooling Characteristics and Subcooling Improvement of TMA-Water Clathrate Compound)

  • 박설현;김창오
    • 한국태양에너지학회 논문집
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    • 제34권6호
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    • pp.85-92
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    • 2014
  • This study carried out experimental on the cooling characteristics of clathrate compound including TMA(Tri-Methyl-Amine ; $(CH_3)_3N$) as a low temperature latent heat storage material. And additive was used for subcooling improvement of TMA-water clathrate compound. The conclusion of above study is as following ; TMA 25wt%-water clathrate compound is shown stable phase change and low subcooling degree. The subcooling was improved in the case ethanol($CH_3CH_2OH$) 0.5wt% is added to TMA 25wt%-water clathrate compound.

Design and Implementation of the Compound Noun Segmentation Algorithm Based on Statistical Information

  • Kim, Chang-Geun;Tack, Han-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권3호
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    • pp.306-310
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    • 2004
  • This paper suggests a reverse segmentation algorithm using affix information and some preference pattern information of Korean compound nouns. The structure of Korean compound nouns is mostly derived from Chinese characters, and it includes some preference patterns utilized as a segmentation rule in this paper. To evaluate the accuracy of the proposed algorithm, an experiment was performed with 36,061 compound nouns. The experiment resulted in getting 99.3% of correct segmentation and showed excellent satisfactory results from the comparative experimentation with other algorithms. Especially, most of the four-syllable or five-syllable compound nouns were successfully segmented without fail.

산국 추출물의 항균력 (Antibacterial Activities of Extracts from Chrysanthemum boreale M.)

  • 양민석;남상해
    • Applied Biological Chemistry
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    • 제38권3호
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    • pp.269-272
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    • 1995
  • 산국과 감국의 용매분획물과 sesquiterpenoid lactones, Compound I, II를 4종의 미생물에 대하여 항균실험을 하였다. 이 중에서 산국의 chloroform분획과 sesquiterpenoid lactones, Compound I에서 B. subtilis과 V. parahaemolyticus에 대하여 항균력이 있었다. 그리고 야생감국의 chloroform분획과 sesquiterpenoid lactones 에서는 항균력이 산국보다 약하게 나타났으며, Compound II와 재배감국의 모든 분획은 미생물에 대하여 항균력이 전혀 나타나지 않았다.

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RECURRENCE RELATIONS FOR HIGHER ORDER MOMENTS OF A COMPOUND BINOMIAL RANDOM VARIABLE

  • Kim, Donghyun;Kim, Yoora
    • East Asian mathematical journal
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    • 제34권1호
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    • pp.59-67
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    • 2018
  • We present new recurrence formulas for the raw and central moments of a compound binomial random variable. Our approach involves relating two compound binomial random variables that have parameters with a difference of 1 for the number of trials, but which have the same parameters for the success probability for each trial. As a consequence of our recursions, the raw and central moments of a binomial random variable are obtained in a recursive manner without the use of Stirling numbers.

Inhibitory Effect of Buthus martensi Karsch Extracts on ${\alpha}$-Glucosidase Enzyme

  • Kim, Eun-Ok;Kim, Shin-Duk
    • International Journal of Industrial Entomology and Biomaterials
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    • 제15권2호
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    • pp.161-164
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    • 2007
  • While searching for ${\alpha}$-glucosidase inhibitors, the active compound was found in a methanol extract of Burthus martensi Kirsch. The separation of the active compound was performed using various chromatography methods and the physico-chemical properties of the purified compound were characterized. The compound showed very potent inhibitory activity against ${\alpha}-glucosidase$ with an $IC_{50}$ value of $5.3\;{\mu}g/ml$. Lineweaver-Burk plot indicated that its inhibition of ${\alpha}-glucosidase$ was competitive.

복합형 전극을 이용한 피부의 전기저항 측정 (SKIN IMPEDANCE MEASUREMENTS USING COMPOUND ELECTRODES)

  • 우응제
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 추계학술대회
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    • pp.98-100
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    • 1991
  • We studied the characteristics of the compound electrode and found that the compound electrode provides the four-electrode method in a compact form. We developed a new method of measuring the skin impedance using simple electrodes at low frequencies. At high frequencies where the effect of internal tissue impedance is not negligible, we used the compensation method using compound electrodes since they measure the voltage right under the skin. At 50 kHz, we measured the real part of the skin impedance of less than $80\;{\Omega}$ on the thorax.

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Enzymatic formation of compound-K from ginsenoside Rb1 by enzyme preparation from cultured mycelia of Armillaria mellea

  • Upadhyaya, Jitendra;Kim, Min-Ji;Kim, Young-Hoi;Ko, Sung-Ryong;Park, Hee-Won;Kim, Myung-Kon
    • Journal of Ginseng Research
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    • 제40권2호
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    • pp.105-112
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    • 2016
  • Background: Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. Methods: Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at $25^{\circ}C$ for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30-80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. Results: Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}$ compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72-96 h, pH 4.0-4.5, and temperature $45-55^{\circ}C$. Conclusion: AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.

Novel Syntheses of 5-Aminothieno[2,3-c]pyridazine, Pyrimido[4',5':4,5]thieno[2,3-c]pyridazine, Pyridazino[4',3':4,5]thieno-[3,2-d][1,2,3]triazine and Phthalazine Derivatives

  • El Gaby, Mohamed S.A.;Kamal El Dean, Adel M.;Gaber, Abd El Aal M.;Eyada, Hassan A.;Al Kamali, Ahmed S.N.
    • Bulletin of the Korean Chemical Society
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    • 제24권8호
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    • pp.1181-1187
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    • 2003
  • Condensation of 4-cyano-5,6-dimethyl-3-pyridazinone 1 with aromatic aldehydes gave the novel styryl derivatives 2a-c. Refluxing of compound 2a with phosphorus oxychloride furnished 3-chloropyridazine derivative 3. Compound 3 was reacted with thiourea and produced pyridazine-3(2H)thione 4. Thieno[2,3-c]- pyridazines 5a-e were achieved by cycloalkylation of compound 4 with halocompounds in methanol under reflux and in the presence of sodium methoxide. Also, refluxing of compound 4 with N-substituted chloroacetamide in the presence of potassium carbonate afforded thienopyridazines 6a-e. Cyclization of compound 6 with some electrophilic reagents as carbon disulfide and triethyl orthoformate furnished the novel pyrimido[4',5':4,5]thieno[2,3-c]pyridazines 12 and 13a-c, respectively. Diazotisation of compound 6 with sodium nitrite in acetic acid produced the pyridazino[4',3':4,5]thieno[3,2-d][1,2,3]triazines 14a-c. Ternary condensation of compound 1, aromatic aldehydes and malononitrile in ethanol containing piperidine under reflux afforded the novel phthalazines 16a-c. Compound 3 was subjected to some nucleophilic substitution reactions with amines and sodium azide and formed the aminopyridazines 17a, b and tetrazolo[1,5-b]-pyridazine 19, respectively. The structures of the synthesized compounds were established by elemental and spectral analyses.

침질침탄시 화합물층의 성장에 따른 표면조도 변화에 관한 연구 (Studies on the Evolution of the Surface Roughness with Development of Surface Compound Layer in Salt Bath Nitrocarburising (Tufftride))

  • 송경석;문경일;김성완
    • 열처리공학회지
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    • 제16권5호
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    • pp.253-259
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    • 2003
  • In this study, to find out the reason of deterioration in surface roughness of steel and cast iron after Tufftride, it has been investigated on the relation between the surface roughness and various factors such as the evolution of compound layer, surface morphology, and surface hardness, and change of pore ratio in the compound layer during Tufftride at $580^{\circ}C$. It is found that the surface roughness was increased with the evolution of compound layer during Tufftride of steel and cast iron. The change of surface roughness after Tufftride was reduced with decreasing tho content of carbon and cementite ($Fe_3C$) in the materials. in the cast irons, the various shaped graphites that was exposed to the surface should induce the discontinuous growth of the compound layer, and this resulted in the incoherent interfaces between matrix and compound layer and the deterioration of surface roughness. In the steels, the existence of cementites in the matrix resulted in the incoherent interfaces between matrix and compound layer. It is considered that during Tufftride the surface roughness must be mainly influenced by the formation of the incoherent interface between compound layer and matrix that is affected by some factors such as the microstructure, the composition, and the hardness of the matrix.