• 제목/요약/키워드: Isolated work

검색결과 437건 처리시간 0.024초

Isolation and Anti-thrombotic Activity of Citric acid 1,5-dimethyl ester from Gastrodia elata

  • Pyo, Mi-Kyung;Park, Kyung-Mi;YunChoi, Hye-Sook
    • Natural Product Sciences
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    • 제6권2호
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    • pp.53-55
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    • 2000
  • In the course of continous work for the discovery of anti-thrombotic constituents from tubers of Gastrodia elata, citric acid 1,5-dimethyl ester was isolated from ethylacetate soluble fraction prepared from the methanol extract. The structure of the compound was determined by the spectroscopic data. The anti-thrombotic effect of this compound was observed with prolonging the bleeding time in thrombin-induced thrombosis model of mice.

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Isolation of 4,4^I-Dihydroxybenzyl Sulfoxide from Gastrodia elata

  • Yun, Hye-Sook;Choi, Hye-Sook;Pyo, Mi -Kyung
    • Archives of Pharmacal Research
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    • 제20권1호
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    • pp.91-92
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    • 1997
  • In the course of continous work on tubers of Gastrodia elata, a new constituent, 4, 4$^{I}$-dihydroxybenzyl sulfoxide was isolated from the ethyl acetate soluble fraction prepared from the methanol extract. The structure of the compound was identified from the elemental analytical and spectroscopic data in comparison with those of non-substituted benzyl sulfoxide.e.

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Grid Independent Photovoltaic Fuel-Cell Hybrid System: Design and Control Strategy

  • Islam Saiful;Belmans Ronnie
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제5B권4호
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    • pp.399-404
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    • 2005
  • In this paper, a hybrid photovoltaic fuel-cell generation system employing an electrolyzer for hydrogen generation and battery for storage purpose is designed and simulated. The system is applicable for remote areas or isolated DC loads. Control strategy has been considered to achieve permanent power supply to the load via the photovoltaic/battery or the fuel cell based on the power available from the sun. MATLAB and SIMULINK have been used for the simulation work. A sensitivity analysis is conducted for various load level based on availability of solar radiation.

Isolation of $n-Butyl-{\beta}-D-fructopyranoside$ from Gastrodia elata Blume

  • Pyo, Mi-Kyung;YunChoi, Hye-Sook;Kim, Yong-Kwon
    • Natural Product Sciences
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    • 제12권2호
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    • pp.101-103
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    • 2006
  • In the course of the continual work on the fresh tubers of Gastrodia elata, a fructoside constituent was isolated from the n-butanol soluble fraction prepared from the methanol extract. The structure of this compound was identified as $n-butyl-{\beta}-D-fructopyranoside$ from various spectroscopic data including $^1H-\;and\;^{13}C-NMR$, HMQC, HMBC, and FABMS.

Further Study on the Constituents of Allium tuberosum leaves

  • Choi, Jae-Sue;Go, Chang-Hak
    • Archives of Pharmacal Research
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    • 제19권1호
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    • pp.60-61
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    • 1996
  • In the course of continuous work on the leaves of Allium tuberosum (Liliaceae), compounds 1 and 2 were isolated from the ethylacetate and butanol-soluble fraction, and identified as N-p-coumaroyl tyramine and bis(p-hydroxyphenyl) ether, respectively, on the basis of spectral data and physicochemical results.

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Trichoderma sp.의 중복기생에 대하여 (Hyperparawitism of Trichoderma sp.)

  • 채희병;유관희;이배함
    • 미생물학회지
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    • 제19권1호
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    • pp.3-7
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    • 1981
  • Attempts were made to develope the method of biological control by application of hyperparasitism on plant disease. The hyperparasitic fungi used in this work was Trichoderma sp. which was isolated from the ginseng growing soil, and the host fungi were Fusarium oxysporum Schlecht and Glomerella cingulata(St) Spau. et Schr. The hyperparasitic fungi identified as Trichoderma viride. It was observed that the hyperparasitic fungi either contact and penetrate into the hyphae of the host or inhibit the growth of host finally destroy of the host cells.

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Chiral Synthesis of Costunolide

  • Sumaila Abu;Jeong, Jin-Hyun;Shin, Dong-Hyok
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.363.1-363.1
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    • 2002
  • Costunolide. a sesquiterpene lactone is isolated from Magnolia Sieboldi. It is known to possess antitumour and anti-inflammatory activities. This compound is synthesized from Ihe easily available decalin dione using the ring cleavage approach to construct the ten-membered ring system. The two keys points in this work are the chiral inductionon the allyl alcohol moiety using Sharpless epoxidation reaction and opening of the eopxide with an organocuprate reagent which leads to a $\alpha$-exomethylene lactone. (omitted)

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경기도지역(京畿道地域)의 유우유방염(乳牛乳房炎)에 관한 조사(調査) 4. 유우유방염(乳牛乳房炎)에서 분리(分離)한 Staphylococcus와 Streptococcus의 항균제(抗菌劑)에 대한 감수성시험(感受性試驗) (Survey of Bovine Mastitis in Gyeonggido 4. Susceptibility of Staphylococcus and Streptococcus Isolates to Chemotherapeutic Agents)

  • 손봉환;김효민;한웅주;정흥환;김수장
    • 대한수의학회지
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    • 제15권1호
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    • pp.101-108
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    • 1975
  • The susceptibility of 536 isolates of Staphylococcus and 313 isolates of Streptococcus to a number of chemotherapeutics were studied. These organisms were isolated from bovine mastitis during 1973 and 1974. In addition to this, the rate of multiple resistance of 425 isolates of Staphylococcus and 164 isolates of Streptococcus, isolated in 1974, to the chemotherapeutics was analysed. The results obtained in this work were summerized as follows: 1. Staphylococcus and Streptococcus isolated in 1974 showed a higher resistance, with 3 exceptions of chemotherapeutics, than the isolates of 1973. 2. Staphylococcus isolated in 1973 and 1974 showed a higher susceptibility than Streptococcus. 3. The strains of Staphylococcus resistant to colistin were 39 strains (9.2%), to colistin and sulfisoxazole 33 (7.8%), to streptomycin, kanamycin, colistin and sulfisoxazole 20 (4.7%), and to penicillin, colistin and sulfisoxazole 18 (4.2%). 4. The strains of Streptococcus resistant to colistin were 17 strains (10.4%), to streptomycin, kanamycin, colistin and sulfisoxazole 13 (7.9%), to colistin and sulfisoxazole 11 (6.7%) and to penicillin, colistin and sulfisoxazole 11 (6.7%).

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랫드 척수후각 단일세포 분리 및 특성에 관한 연구 (Isolation and Electrical Characterization of the Rat Spinal Dorsal Horn Neurons)

  • 한성규;류판동
    • 대한약리학회지
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    • 제32권2호
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    • pp.283-292
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    • 1996
  • The spinal dorsal horn is the area where primary afferent fibers terminate and cutaneous sensory information is processed. A number of putative neurotransmitter substances, including excitatory and inhibitory amino acids and peptides, are present in this region. In this study, single neurons of the spinal dorsal horn were acutely isolated and the properties of whole cell current and responses to excitatory and inhibitory neurotransmitters were studied by patch clamp technique. Transverse slice ($(300{\mu}m$) of lumbar spinal cords from young rats$(7{\sim}14\;days)$ were sequentially treated with two pretenses(pronase 0.75 mg/ml and thermolysin 0.75 mg/ml), then single neurons were mechanically dissociated. These neurons showed near-intact morphology such as multipolar, ellipsoidal and bipolar, and pyramidal cells and we recorded the typical whole cell currents of $K^+$, $Ca^{2+}$ and ligand-operated channels from these neurons. Glutamate $(30{\mu}M)$ and N-methyl-D-aspartate(NMDA, $30{\mu}M)$ induced inward currents of $117{\pm}12.4$ pA(n=5) and $49{\pm}6.9$ pA(n=3), respectively. Glycine $(1{\mu}M)$ potentiated glutamate-induced currents $4{\sim}5$ times and NMDA-induced currents $8{\sim}10$ times. In addition, glycine $(30{\mu}M)$ induced Inward current ($31{\pm}6.1$ nA, n=2), which was rapidly desensitized after the peak to a new steady-state level. However, the inward currents induced by ${\gamma}-amino$ butyric acid(GABA, $1{\mu}M$) decreased continuously after the peak($226{\pm}41.6$ pA, n=3) under the similar experimental condition. The ionic currents and pharmacological responses of isolated neurons in this work were similar to those observed in vivo or in vitro spinal cord slice, indicating that acutely isolated neurons could be effectively used for further pharmacological studies.

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Ergostane-Type Steroids from Korean Wild Mushroom Xerula furfuracea that Control Adipocyte and Osteoblast Differentiation

  • Lee, Seoung Rak;Choi, Jin Hee;Ryoo, Rhim;Kim, Jin-Chul;Pang, Changhyun;Kim, Seon-Hee;Kim, Ki Hyun
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1769-1776
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    • 2020
  • As part of our current work to discover structurally and/or biologically novel compounds from Korean wild mushrooms, we isolated five ergostane-type steroids (1-5) from the fruiting bodies of Xerula furfuracea via repeated column chromatographic separations and HPLC purification. The chemical structures of the isolated steroids were shown to be (22E,24R)-24-methylcholesta-4,22-diene-3,6-dione (1), ergosta-7,22-diene-3β,5α,6β-triol (2), ergosta-7,22-diene-3β,5α,6β,9α-tetraol (3), (22E,24R)-5α,8α-epidioxyergosta-6,22-diene-3β-ol-3-O-β-D-glucopyranoside (4), and (22E,24R)-5α,8α-epidioxyergosta-6,9,22-triene-3β-ol-3-O-β-D-glucopyranoside (5)based on comparison of the data regarding their spectroscopic and physical properties with those of previous studies. Notably, this is the first report on the presence of the identified steroids (1-5) in this mushroom. We tested compounds 1-5 to determine their effects on adipogenesis and osteogenesis in the mouse mesenchymal stem cell line C3H10T1/2 and found that compounds 4 and 5 suppressed the differentiation of stem cells into adipocytes. Notably, in addition to its suppressive effect on adipogenesis, compound 5 was also shown to promote the osteogenic differentiation of stem cells. These findings demonstrate that the bioactive compounds isolated might be effective for the treatment of menopause-associated syndromes, such as osteoporosis and obesity, as the isolated compounds were shown to suppress adipogenesis and/or promote osteogenesis of stem cells.