• 제목/요약/키워드: $CO_2$-Acetonitrile

검색결과 96건 처리시간 0.025초

Analysis of DA-6034. a New Flavonoid Derivative in Biological Fluids by Fluorescence Detector

  • Jang, Ji-Myun;Park, Kyung-Jin;Lee, Jong-Jin;Kim, Dong-Goo;Shim, Hyun-Joo;Son, Mi-Won;Kim, Dong-Sung;Kim, Soon-Hoe;Yoo, Moo-Hi
    • 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.403.2-403.2
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    • 2002
  • A high performance liquid chromatographic method was developed for the determination of DA-6034 in biological fluids using fluorescence detector. The method involved deproteinization of biological sample with the same volume of acetonitrile, 0.2M zinc sulphate. and 0.15M barium hydroxide. The aliquot of supernatant was injected onto Nova-pak C18 column and detected by fluorescence detector. Emission and excitation wavelength of detector were 336nm and 440nm. (omitted)

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탈착용매에 따른 PAHs 흡착매체의 탈착효율 평가 연구 (A Study on Desorption Efficiency of PAHs according to Desorption Solvents by HPLC with Sonication Extraction)

  • 홍좌령;이지은;정명구;최광민
    • 한국산업보건학회지
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    • 제26권3호
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    • pp.307-316
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    • 2016
  • Objectives: In general, NIOSH method 5506 is most widely used for the occupational exposure measurement of PAHs, but 2-4 ring PAHs have poor desorption efficiency, especially for a filter. The purpose of this study was to determine a method to increase the desorption efficiency of 16-PAHs using an ultrasonic extraction procedure. Methods: Test samples prepared spiked XAD-2 tubes and PTFE filters in the range of $0.01-1.0{\mu}g/mL$ for desorption efficiency study. Four different extraction solvents, acetonitrile, acetone, tetrahydrofuran and dichloromethane, were tested in order to select the most suitable solvent for the extraction of the 16 PAHs. The addition of dimethyl sulfoxide and sonication time were considered in order to determine the method with the highest extraction efficiency. All samples were made in three sets and analysis was replicated seven times by HPLC. Results: Acetonitrile and acetone were the optimized as an extraction solvent and desorption efficiency of 2-ring PAHs such as naphthalene, acenaphthylene were increased 3~19% with dimethyl sulfoxide for XAD-2. Acetone was the best extraction solvent for PTFE filter and the desorption efficiency was increased 3~13% for 2- to 4-ring PAHs. The optimum sonication time was 60 minutes and desorption efficiency increased with extraction time. Conclusions: As a result, the best extraction solvent was acetone with dimethyl sulfoxide for ultrasonic extraction procedure and the desorption efficiency of this method was better than NIOSH 5506's. This study could be applied as a method for occupational exposure measurement of PAHs.

녹차에서 카테킨 화합물의 초임계 유제 추출 (Supercritical Fluid Extraction of Catecnin Compounds from Green Tea)

  • 나영진;이윤우;김재덕;노경호
    • KSBB Journal
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    • 제16권4호
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    • pp.327-331
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    • 2001
  • 전라남도 보성산 녹차로부터 유용성분인 카테킨 화합물을 초임계 이산화 탄소와 첨가제를 사용하여 추출하고 역상 고성능 액체 크로마토그래피(RP-HPLC)를 사용하여 분석하였다. LiChrospher 100RP-18(15 $\mu$m)로 충진된 column을 이용하여 0.05% phosphoric acid가 포함된 물과 acetonitrile을 이동상으로 사용하였으며 구배용매 조성법을 적용하였다. 이동상의 조성에 따른 체류인자의 조절을 통해 EGCG를 분리하였다. 각각의 초임계 추출법에 따른 EGCG의 추출량을 비교한 결과, 초임계 유체에 극성물질을 포함하는 경우가 녹차의 유용 성분인 EGCG의 추출량이 가장 많았다. 그러나 ethanol에 의한 용매 추출법은 초임계 유체에 의한 추출법보다 EGCG에 대해 많은 추출양과 선택적인 고순도 분리가 가능하였다.

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Cross Interaction Constants As a Measure of the Transition State Structure (Part 2). Nucleophilic Substitution Reactions of Phenacyl Bromides with Aniline in Methanol-Acetonitrile Mixtures

  • Lee, Ik-Choon;Kim, In-Chul
    • Bulletin of the Korean Chemical Society
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    • 제9권3호
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    • pp.133-135
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    • 1988
  • Kinetics and mechanism of the nucleophilic substitution reactions of phenacyl bromides with anilines in methanol-acetonitrile mixtures at $45.0^{\circ}C$ are reported. The reaction is found to proceed via $S_N2$ process, but the magnitudes of cross interaction constants, ${\rho}_{XY}$, between substituents X in the nucleophile and Y in substrate were unusually small, even after allowing for the fall off due to non-conjugative intervening -CO group in the reactant. As in the other phenacyl derivatives, the resonance shunt phenomenon was invoked to explain the remarkable diminuation of the $|{\rho}_{XY}|$ values.

아세토니트릴 첨가가 물유리 기반 실리카 에어로겔의 기공구조에 미치는 영향 (The Effect of Acetonitrile on the Texture Properties of Sodium Silicate Based Silica Aerogels)

  • 김영훈;김태희;심종길;박형호
    • 마이크로전자및패키징학회지
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    • 제25권4호
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    • pp.143-148
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    • 2018
  • 물유리 기반 실리카 에어로겔은 실리카 알콕사이드 기반 실리카 에어로겔에 비해 단가가 싸지만 기공률 및 비표면적과 같은 기공 특성이 상대적으로 열악하여 수요가 감소되고 있다. 이를 해결하기 위해 본 연구에서는 졸 상태에서 건조 제어 화학 첨가제(drying control chemical additive)인 아세토니트릴(acetonitrile)을 첨가하여 물성을 향상시키고자 하였다. 상압 건조 물유리 기반 실리카 에어로겔은 졸-겔 공정을 통해 제조되었으며, 졸 상태에서 물유리와 0, 0.05, 0.1, 0.15, 0.2의 몰 비율로 아세토니트릴을 첨가하여 실험을 수행하였다. 최종 생성물의 물성은 퓨리에 분광기(Fourier transform infrared), 접촉각측정기(contact angle measurement), Brunauer-Emmett-Teller 및 Barrett-Joyner-Halenda 분석기와 전계방사형 주사전자현미경(field emission scanning electron microscopy)를 이용하여 분석하였다. 졸 상태에서 물유리와의 몰 비율이 0.15인 아세토니트릴을 첨가한 샘플의 경우, 높은 비표면적 ($577m^2/g$), 높은 기공 부피 (3.29 cc/g), 높은 기공률 (93%)을 보유하여 실리카 알콕사이드 기반 실리카 에어로겔과 유사한 기공구조를 나타낼 수 있음을 확인하였다.

항염증 활성을 갖는 탱자 추출물 합성 (Synthesis of Trifoliate Orange Extract Having Anti inflammation Activities)

  • 김덕술;노언주
    • 한국응용과학기술학회지
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    • 제28권2호
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    • pp.196-202
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    • 2011
  • Coumarin derivatives were shown to possess valuable pharmacological properties such as anticancer/anti carcinogenic, anti-inflammatory, anti helicobacter, anti genotoxic, neuroprotective and dietary effect. In this study, novel coumarin derivatives structurally related to 7-geranyloxycoumarin were effectively synthesised in good yields by $Cs_2CO_3$/acetonitrile in mild condition. The synthesis of geranyloxycoumarin derivatives in weak base($Na_2CO_3$, $K_2CO_3$, $Cs_2CO_3$ etc)/$CH_3CN$ at room temperature obtained in good yield. On the other hand, the reaction of geranyloxycoumarin formation in strong base(NaOH, KOH, CsOH etc)/$CH_3CN$ at reflux condition obtained in low yield.

Lovastatin을 생산하는 식용버섯 선발과 HMG-CoA reductase 저해 효과 (Screening of Edible Mushrooms for the Production of Lovastatin and its HMG-CoA Reductase Inhibitory Activity)

  • 이재원;이수민;곽기섭;이지윤;최인규
    • 미생물학회지
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    • 제42권2호
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    • pp.83-88
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    • 2006
  • 국내에서 식용버섯으로 이용되고 있는 8종 균주의 자실체와 균사체로부터 콜레스테롤 합성을 저해하는 lovastatin 생산과 고지혈증 억제활성을 탐색하였다. TLC 분석으로 lovastatin생산 유무를 검색한 결과 자실체와 균사체의 추출물에 대해 Rf값이 표준물질콰 같은 약 0.46에서 뚜렷한 밴드가 형성됨을 확인하였다. 자실체로부터 lovastatin 추출을 위한 용매로는 water/acetonitrile/methanol (5:2.5:2.5)을 사용하였을 매 가장 효과적인 lovastatin 생산량을 보였다. Lovastatin 생산량은 자실체 중에서는 Pleurotus ostreatus가 0.98 mg/g (dry biomass)으로 가장 높은 생산량을 나타냈고 균사체 배양액 추출물에 대해서도 P. ostreatus가 21.90 mg/L로 높은 생산량을 나타냈다. 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase 저해활성에서는 자실체에서 P ostreatus가 67.8%, 균사체에서 P. ostreatus와Laetiporus sulphureus가 각각 37.2%, 29.1%의 저해활성을 보였다. L. sulphureus는 lovastatin 생산량에 비해 높은 저해활성을 나타내서 lovastatin 이외의 다른 고지혈증 억제물질을 GC/MS로 분석한 결과 대사산물로 분비되는 식물성 sterol 물질인 campesterol과 gamma-sitosterol이 검출되었다.

Vinylation of $\beta$-Acetoxyvinyl Mercurials with Olefins by Palladium (Ⅱ) Salt

  • Kim, Jin-Il;Lee, Jong-Tae
    • Bulletin of the Korean Chemical Society
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    • 제7권2호
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    • pp.142-145
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    • 1986
  • Vinylation of highly hindered ${\beta}$-acetoxyvinyl mercurials with olefins in acetonitrile at room temperature in the presence of cupric chloride, as a reoxidant for the palladium, and a catalytic amount of $LiPdCl_3$ gave the corresponding conjugated dienes in moderate to good yields. The (E) or (Z) geometry in vinyl mercurials was retained in the vinylated products. The reaction was tolerant of a wide variety of functional groups ($CO_2$R, CN, OR, OAc) on either the vinyl mercurial or olefin compounds.

18F을 표지 암 영상용 클로트리마졸 유도체의 합성 (Synthesis of 18F Labeled Clotrimazole Derivatives as a Potential PET Imaging Agent)

  • 정순재;김인종;박정훈;이흥래;김상욱;허민구;최상무;양승대;유국현
    • 방사선산업학회지
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    • 제4권1호
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    • pp.7-11
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    • 2010
  • Clotrimazole [1-{(2-chlorophenyl)-diphenylmethyl}-1H-imidazole, CLT] has been reported to inhibit the proliferation of vascular endothelial and act as an in vitro anti-VEGF drug. It is also shown to inhibit angiogenesis in an animal model. The radioisotope labeled clotrimazole derivative can be utilized to monitor the physiologic processes of cancer. In this study, we synthesized [$^{18}F$]fluoride labeled clotrimazole derivatives as a new tumor imaging agent for PET. The references were prepared by a refluxing with clotrimazole and an excess of fluoroalkyltosylate in acetonitrile for 36 h and clotrimazole reacted with ditosylalkane to give precursors. [$^{18}F$]Fluoride labeled reaction was performed with precursor in Kryptofix[2.2.2]/$K_2CO_3$ for 10 min at $80^{\circ}C$. The radiolabeling mixture was passed through a silica Sep-Pak cartridge to remove $^{18}F^-$. The [$^{18}F$]F-clotrimazole derivatives were synthesized with a 20~25% yield. In the radiofluorination step, we used acetonitrile and DMSO as a solvent and observed a higher yield at the acetonitrile (25%) reaction compared with the DMSO reaction (5%).