• 제목/요약/키워드: Organic Constituents

검색결과 245건 처리시간 0.025초

Chemical Constituents of the Himalayan Yew, A Review

  • Das, Biswanath;Anjani, G.
    • Natural Product Sciences
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    • 제4권4호
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    • pp.185-202
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    • 1998
  • A large number of chemical constituents have been reported from the Himalayan yew [Taxus baccata (Linn) or T. wallichiana (Zucc)]. These constituents are mainly taxoids and phenolics. Taxol, a lead anticancer agent, is the most important constituent. Other compounds have also been found to possess interesting biological properties. The literature concerning the chemistry and bioactivity of the constituents of the Himalayan yew has been briefly reviewed.

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Modified Micellar Electrokinetic Capillary Chromatography에 의한 폭약 성분의 분리능 향상 (Improved Separation of Organic Explosives by Modified Micellar Electrokinetic Capillary Chromatography)

  • 박성우;양영근;홍성욱;김택제
    • 분석과학
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    • 제10권5호
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    • pp.325-331
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    • 1997
  • 계면활성제로 sodium dodecylsulfate(SDS)를 이용한 micellar electrokinetic capillary chromatography (MECC) 방법을 이용하여 유기 폭약 성분을 신속하고 정확하게 분석할 수 있는 방법을 연구하였다. 완충요액으로는 2.5mM borate와 25mM SDS(pH 8.5)를 사용하였고, 완충용액에 1M urea와 10% 유기 용매(acetonitrile, methanol 및 ethanol)를 첨가한 결과 분리능이 향상되는 현상을 관찰할 수 있다. 15종의 폭약 혹은 그 구성 성분을 MECC 방법으로 분리한 결과 RDX/TNB 및 DNN/DEP를 제외한 성분을 분리할 수 있었고, 검출한계는 1~4ppm으로 나타났다.

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수생식물 생태계에 있어서 낙엽의 구성성분의 유실률 I. 낙동강 삼각주지역의 갈대 초지 (The Removal Rate of the Constituents of the Litters in the Aquatic Plant Ecosystems I. Phragmites longivalvis Grasslands in a Delta of the Nakdong River)

  • 장남기;오경환
    • 아시안잔디학회지
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    • 제9권4호
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    • pp.331-342
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    • 1995
  • An investigation was performed to reveal the removal rates of organic constituents of the litters in a Phragmithea longivalvis grassland in a Delta of the Nakdong River, The removal rates of the inorganic and organic materials are determined by the mathematical models. The removal rates and time required to decay up to a percentage of each organic constituent were calculated using these new models. The removal rates of cold water soluble fractions, other carbohydrates, hot water soluble fractions, cellulose, crude fat, lignin and crude protein were 2.67, 1.39, 1.25, 1.02, 0.92, 0.49 and 0.47, respectively, The periods required to reach half time to the steady state of the removal and accumulation for cold water soluble fractions, other carbohydrates, hot water soluble fractions, cellulose, crude fat, lignin and crude protein of the litter were 0.26, 0.50, 0.55, 0.68, 0.75, 1.41 and 1.48 years, respectively.

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고수의 향미성분에 관한 연구 (A Study on the flavor constituents of the Coriander(Coriandrum sativum L))

  • 김경자;최옥자;김용두;강성구;황금희
    • 한국식품조리과학회지
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    • 제17권1호
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    • pp.80-90
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    • 2001
  • This study was carried out to investigate to proximate compositions, free sugars, organic acids, amino acids, and volatiles from the fresh leaf, root and seed of coriander. The research results are as follows: Moisture was 79.93% in the leaf, 81.89% in the root. Crude protein, crude lipid and crude ash were the highest in the seed. Ascorbic acid was 65.4mg% in the leaf and 37.83mg% in the root. Glucose, fructose and sucrose were the major free sugars. Glucose was 7.92mg% and fructose 7.51mg% in the leaf. Sucrose was 17.34mg% in the root, highest level. Among organic acids, malic acid was 354.55mg% in the leaf, the highest level. The content rate of organic acids was high in the order of leaf, seed and root. The content rate of total amino acid was high in the order of seed, root and leaf. Glutamic acid and aspartic acid were high in the leaf and root. Glutamic acid and proline were high in the seed. The content rate of free amino acid is the same as that of total amino acid. Glutamic acid and serine were high in the leaf and seed. Glutamic acid and treonine were high in the root. The contents of total amino acid in each parts of the coriander was higher than that of free amino acid, The composition of amino acid in the total amino acid and free amino acid was different. The volatile constituents were extracted by steam distillation method and analyzed by GC-Mass. The content of the volatile constituents was 45.31mg% in the leaf, (E)-2-decenal was the highest, followed by decanal, 2-dodecenal, (E)-2-decen-1-ol in order, aldehyde and alcohol was major constituents. The content of the volatile constituents was 36.01mg% in the root and 54.37mg% in the seed. linalool was the highest in the root and seed. it was 22.27 %, 53.67% in root and seed.

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Taxoids, Lignans, and Simple Phenolic Compounds from a Sample of the Needles of Himalayan Taxus baccata

  • Das, Biswanath;Anjani, G.;Kashinatham, A.;Venkataiah, B.;Rao, S. Padma
    • Natural Product Sciences
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    • 제4권2호
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    • pp.78-83
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    • 1998
  • Chemical investigation on a sample of the needles of Himalayan Taxus baccata has resulted in the isolation of several taxoids including taxol (1) 10-deacetyl-baccatin III (2) and 2-deacetoxytaxinine J (3) along with different lignans (6 and 7) and simple phenolics (8, 9, 10, 11 and 12). The occurrence of 4-(4'-hydroxyphenyl)-butane-2-one and 4-(4'-hydroxyphenyl)-trans-but 3-ene-2-one (8) in Taxus species is reported for the first time. The $^{13}C-NMR$ spectral data of two rearranged taxiod constituents, brevifoliol (4) and 13-decinnamoyltaxchinin B (5) are presented. The acid-catalyzed decomposition of taxol has been discussed. The synthesis of other two constituents, rhododendrol (10) and hibalactone (7) has been described.

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Impact of Dissolved Wastewater Constituents on Laccase-Catalyzed Treatment of Bisphenol A

  • Kim, Young-Jin
    • 한국환경보건학회지
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    • 제30권2호
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    • pp.161-166
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    • 2004
  • The impact of dissolved wastewater constituents on the treatment of synthetic bisphenol A (BPA) solutions was investigated under a variety of reaction conditions. The laccase enzyme from Trametes vesicolor was used for the BPA treatment. The constituents studied included various inorganic salts, organic compounds and heavy metal ions. BPA degradation was inhibited by sulfate, thiosulfate, sulfide, nitrite, and cyanide ions at 25 mg/$\ell$, 100mg/$\ell$, 25 mg/$\ell$ 150 mg/$\ell$, and 2.5 mg/$\ell$, respectively. However, the inhibitive effects of sulfide and sulfite on BPA degradation were diminished by additional aeration to oxidize them. Formaldehyde significantly reduced the rate of BPA degradation at 1.0% among organic compounds studied. Among heavy metal ions tested, Fe(II) substantially suppressed BPA removal at 1 mM. MgCl$_2$ and CaCl$_2$ exhibited great inhibition of BPA degradation at 25mM.

Effects of Constituents in CNT Pastes on the Field Emission Characteristics of Carbon Nanotubes

  • 김석환;이동구
    • 한국전기전자재료학회논문지
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    • 제24권3호
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    • pp.245-249
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    • 2011
  • Carbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. However, the lifetime of CNT emitters which are formed by screen printing technique is not guaranteed yet, because the constituents in CNT paste affect the lifetime of CNTs. The CNT pastes for screen printing are normally composed of organic vehicles (nitro cellulose, ethyl cellulose, etc) and additives (glass frits, indium tin oxide (ITO), etc) with CNTs. In this study, the effects of constituents in CNT pastes on the lifetime and emission characteristics of CNTs were investigated by thermal and electrical analysis. Use of glass frits worsened the lifetime and electron emission of CNTs. However, an addition of ITO to CNT paste rather improved the lifetime of CNTs. Degradation of CNTs was small when nitro cellulose was used in CNT paste as an organic vehicle.

Chemical Constituents and Pharmacological Activities of Hedyotis diffusa

  • Xu, Bao-Jun;Sung, Chang-Keun
    • Natural Product Sciences
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    • 제11권1호
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    • pp.1-9
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    • 2005
  • The chemical constituents from Hedyotis diffusa Willd and their pharmacological activities were summarized. It has been known data that this herb contains anthraquinones, terpenoids, steroids, flavonoids, organic acid, and polysaccharides. The studies of pharmacology have shown that Hedyotis diffusa Willd possess various levels of activities such as anticancer, anti-inflammatory, immunostimulatory, antioxidative, neuroprotective, and hepatoprotective activities.