• 제목/요약/키워드: Heterocyclic

검색결과 314건 처리시간 0.032초

Liquid Membrane Permeation of Nitrogen Heterocyclic Compounds Contained in Model Coal Tar Fraction

  • Kim, Su-Jin;Kang, Ho-Cheol;Kim, Yong-Shik;Jeong, Hwa-Jin
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1143-1148
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    • 2010
  • We investigated the separation of nitrogen heterocyclic compound (NHC) contained in a model coal tar fraction comprising four kinds of NHC [indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)], three kinds of bicyclic aromatic compound (BAC) [1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN) mixture with ten structural isomers (DMNs; regarded as one component)], biphenyl (Bp) and phenyl ether (Pe) by liquid membrane permeation (LMP). A batch-stirred tank was used as the permeation unit. An aqueous solution of saponin and n-hexane were used as the liquid membrane and the outer oil phase, respectively. Yield and selectivity of individual NHC was much larger than that of BAC, Bp and Pe. Increasing the initial mass fraction of the saponin to the membrane solution ($C_{sap,0}$) and the initial volume fraction of O/W emulsion to total liquid in a stirred tank (${\phi}_{OW,0}$) resulted in deteriorating the yield of individual NHC, but increasing the stirring speed (N) resulted in improving the yield of each NHC. With increasing $C_{sap,0}$, the selectivity of each NHC based on DMNs increased. Increasing ${\phi}_{OW,0}$ and N resulted in decreasing the selectivity of individual NHC based on DMNs. At an experimental condition fixed, the sequence of the yield and selectivity in reference to DMNs for each NHC was Q > Qu = iQ > In. Furthermore, we compared LPM method with methanol extraction method in view of the separation efficiency (yield, selectivity) of NHC.

Photoluminescent Properties of Eu(III) in the Composite Heterocyclic Ligands/Crown Ether Systems

  • Liu, Hong Guo;Jang, Ki-Wan;Feng, Xu Sheng;Kim, Chang-Dae;Yoo, Young-Jae;Lee, Yong-Ill
    • Bulletin of the Korean Chemical Society
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    • 제26권12호
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    • pp.1969-1974
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    • 2005
  • Composite systems of $Eu(phen)_2Cl_3{(H_2O)}_2$, Eu(DN-bpy)$(phen)Cl_3{(H_2O)}_2$ and Eu(DB-bpy)$(phen)Cl_3{(H_2O)}_2$ (DNbpy: $4,4^\prime$-Dinonyl-$2,2^\prime$-dipyridyl; DB-bpy: $4,4^\prime$-Di-tert-butyl-$2,2^\prime$-dipyridyl) with crown ethers of Benzo-15-crown-5 (B15C5), Benzo-18-crown-6 (B18C6), 18-crown-6 (18C6), Dibenzo-18-crown-6 (DB18C6) and Dibenzo-24-crown-8 (DB24C8) were fabricated successfully and characterized by using photoluminescent spectroscopy and luminescent lifetime measurements. All composites formed show high luminescence mainly in red region. It was found that the heterocyclic ligands such as phen, DN-bpy and DB-bpy as well as the crown ethers have great influences on the photoluminescent properties of $Eu^{3+}$ ion. The environment around $Eu^{3+}$ ion in the composite systems changes greatly,presumably the variation of the first coordination sphere. The $Eu^{3+}$ ion occupies higher symmetrical environment and in more than one kind of symmetrical site in the composite systems studied in this work.

당(糖) 분해생성물의 돌연변이원성 억제작용 (Desmutagenic Action of Sugar Degradation Products)

  • 김선봉;김인수;염동민;박영호
    • 한국식품과학회지
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    • 제20권1호
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    • pp.119-124
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    • 1988
  • 식품의 안전성 평가를 위한 기초자료를 얻기 위하여, 식품의 가공, 저장 및 조리중에 식품성분간의 상호반응인 Maillard 반응을 이용하여 당의 분해로 생성되는 각종 카르보닐화합물을 강력한 돌연변이원성물질로 알려진 Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 및 IQ에 각각 작용시켜서 이들 물질의 돌연변이성 억제효과를 연구 검토하였다. 그 결과, 카르보닐화합물에 의하여 돌연변이원성물질의 돌연변이원 활성이 크게 억제되었다. 사용한 카르보닐화합물중 ${\alpha}$-hydroxycarbonyl 화합물의 경우, glyceraldehyde, glycolaldehyde 및 dihydroxyacetone에서 돌연변이원성 억제효과가 크게 나타났다. ${\alpha}$-dicarbonyl 화합물의 경우, diacetyl에서 그 억제효과가 우수한 것으로 나타서, 전반적으로 ${\alpha}$-dicarbonyl 화합물이 ${\alpha}$-hydroxycarbonyl 화합물보다 돌연변이성 억제효과가 높게 나타났다. 한편, 공시한 카르보닐화합물 단독으로는 돌연변이 성을 나타내었으나, Trp-P-1등의 돌연변이원성물질과의 상호반응로 이들 두 물질의 돌연변이성이 동시에 소실되는 것이 입증되었다.

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두충차와 감잎차의 향기성분 (The Aroma Components of Duchung Tea and Persimmon Leaf Tea)

  • 최성희
    • 한국식품과학회지
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    • 제22권4호
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    • pp.405-410
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    • 1990
  • 국산 대용차 중 시판되고 있는 두충차와 감잎차의 향기성분을 연속증류 추출법으로 추출하여 GC-MS에 의하여 분석, 동정하였다. 두충차에서는 hydrocarbon류 3종, alcohol류 17종, ketone류 15종, aldehyde류 16종, acid류 8종, hetero 고리화합물류 8종과 phenol류 2종을 포함한 총 77종류의 향기성분을 확인하였다. 두충차에 많이 존재하는 ketone류(14.59%) aldehyde류(23.31%)와 hetero 고리화합물(16.71%)들은 두충차의 특징인 달콤하고 한약재에 가까운 향기에 기여한다고 생각된다. 감잎차에서는 hydrocarbon류 10종, alcohol류 17종, ketone류 11종, aldehyde류 13종, ester류 8종, acid류 6종, hetero 고리화합물 5종과 phenol류 1종을 포함한 총 71종을 확인 하였다. 감잎차에는 향기의 기여도가 낮은 hydrocarbon류의 함량(10.40%)이 두충차에 비해 많았고 alcohol류의 함량(25.57%)이 현저하게 많아 은은하고 순한 감잎차의 특유향에 기여한다고 생각된다.

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