• Natural Product Sciences
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• v.20 no.2
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• pp.91-94
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• 2014

Column chromatographic separation of the MeOH extract from the tubers of Bletilla striata yielded seven phenolic components including four phenanthrenes, 3,7-dihydroxy-2,4-dimethoxyphenanthrene (1), 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene (2), 9,10-dihydro-4,7-dimethoxyphenanthrene-2,8-diol (3), and 9,10-dihydro-1-(4'-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,8-diol (4) and three stilbenes, gigantol (5), 3',4"-dihydroxy-5',3",5"-trimethoxybibenzyl (6), and batatasin III (7). Their structures were determined on the basis of NMR spectroscopic data. Among them, compound 2, 3, and 6 were reported for the first time from this plant. The isolated compounds (1-7) were tested for cytotoxicity against four human tumor cell lines in vitro using a Sulforhodamin B bioassay.

• Journal of the Korean Chemical Society
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• v.11 no.3
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• pp.85-88
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• 1967

The main object of this experiment is to provide a systematic approach to the reaction mechanism in the photolysis of 5-phenyl-1,2,3,4-tetrazole during which the formation of C-phenyl-nitrile-imine of 1.3-dipole was expected. So the occurrence of 1,3-dipole-addition was examined but not observed despite the formation of nitrile-imine. 3,6-diphenyl-1,2,4,5-tetrazine (IV); 3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine (III); 3,5-diphenyl-1,2,4-triazole; 4-amino-3,5-diphenyl-1,2,4-triazole; benzonitrile; ammonia and nitrogen were isolated as final products of this reaction.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.132-132
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• 1993

정상세포의 암세포로의 전환에 수반하는 세포표면상에 당구조 변화가 주목을 받고 있으며 이에 탄수화물이 세포간의 상호작용, 성장 등에 중요한 역할을 하리라고 생각된다. 따라서, 당구조 변화를 야기 시키는 당분해소효소나 전이활성 효소의 활성이 주요한 임상적 지표가 될 수 있다. 또한 천연물에서 유래된 다당류 등이 면역증강 효과를 나타내면서 항종양 효과를 보여준다. 이와같은 일을 원활히 수행하기 위해서는 당을 분석하는 기술이 필요하다. 당을 분석하는 방법으로 많이 이용된 것 중의 하나가 유도체를 만들어 GC에 의해서 확인하는 것이고 또한 당은 chromophore가 없기 때문에 굴절율의 검출기를 이용한 HPLC에 의해서도 분석이 가능하다. HPLC에 의한 또 다른 방법으로 당의 환원당 말단에 형광기를 결합시켜 감도를 매우 높게하여 역상 칼람을 이용해 당을 분리할 수 있다. 환원당에 결합시킬 수 있는 물질로는 대부분 amine기를 띄고 있고 결합하여 형광을 나타내는 특징을 지니고 있다. 본 연구는 형광기를 결합시켜 전기영동과 HPLC에 의해 동시에 추적이 가능한 물질을 결합시켜서 분석을 용이하게 한 방법을 이용하여 단당류를 $C_{18}$ column에 의해서 분리하였고 또한 모델로서 면역증강제로 사용되는 운지버섯 및 영지버섯 다당류와 생약에서 분리한 지유의 당을 분석하였다. 현재까지의 결과로 가장 좋은 방법은 $C_{18}$-->phenyl column을 연결하여 isocratic 방법으로 분리하였을 때이었다. 버섯의 당은 대부분이 glucose로 이루어졌고 지유는 arabinose가 주 구성성분이었다. 위의 분석 기술을 이용하면 피코몰 범위내에서 정확한 구조를 가진 항암효과의 올리고당 및 암세포의 발현에 따른 당단백질의 당의 구조를 규명하는데 도움을 줄 수 있다.aeonol이 aspirin과 같거나 강한 사망 억제 효과가 있었다.cyclopropyl-7-(2-furanyl) -6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid (compound 4), 1-cyclopropyl-7-(2-thiophenyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid (compound 6) ,1-cyclopropyl-7-(3-pyridinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid (compound 8), 1-cyclopropyl-7-(2-fluoro-3-pyridinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid (compound 10)를 합성하였다.10^{－7}$ M)에 의한 단백인산화에 대하여는 더 미약한 억제-효과를 나타내었다. 이상의 결과는 PDE-1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.603-607
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• 1994

New cephalosporin antibiotics,7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-[(substituted pyrimidin-2-yl)thiomethyl]-3-cephem-4-carboxylic acid derivatives(2a∼2d) were synthesized. These new cephalosporin derivatives were prepared by the introduction of pyridinylthiomethyl moiety in 3-position and thiazine group in 7-position of 7-ACA. Antibacterial activities of these compounds were examined and the relationship between structure and activities were studied. As the result, these compounds showed low antibacterial activities compared to cefotaxim used as control.

• Applied Biological Chemistry
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• v.27 no.2
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• pp.64-72
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• 1984

Alachlor, 2-chloro-2, '6'-diethyl-N-(methoxymethyl) acetanilide, which had been incubated in the flooded paddy soils yielded 1-formyl-2,3-dihydro-7-ethylindole, 2,6-diethylaniline, 2,6-diethylacetanilide, 2,6-diethyl-N-(methoxymethyl) acetanilide, 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide, and three unidentifiable compounds as its degradation products. The water-soluble products of Alachlor in soil suspensions increased with incubation periods and similar results were obtained from the incubation of Rhizoctonia solani, as verified by use of the ring $-^{14}C-$labeled Alachlor. Streptomyces lavendulae Ru 3340-8 produced 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide as the major degradation product as much as 25%, whereas Bacillus brevis IFO 3331, Bacillus cruciviae, and Pseudomonas putida did not produce it.

• YAKHAK HOEJI
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• v.44 no.4
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• pp.325-333
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• 2000

The 1,3-dipolar cycloaddition reaction of the quinoxaline 4-oxides 2 with 2-chloroacrylonitrile gave the 2,3-dihydro-1H-1,2-diazepino[3,4-b]quinoxalines 3, which were converted into the 2,3,4,6-tetrahydro-1H-1,2-diazepino[3,4-b]quinoxalines 5-7. The reaction of compounds 3 with selenium dioxide in acetic acid/water resulted in ring transformation to give the 1,4-dihydro-4-oxopyridazino[3,4-b]quinoxalines 8.

• Journal of the Korean Chemical Society
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• v.33 no.2
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• pp.247-256
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• 1989

4-Acetyl-5,6-dihydro-2-methyl-1,4-thiazine carboxylic acid derivatives 24 were prepared by ring expansion of corresponding thiazolidine sulfoxides. Oxidation of 2-methyl-1,3-thiazolidine-2-acetic acid derivatives 12 gave a mixture of cis and trans sulfoxides, 14 and 15. Assignments of the cis and trans sulfoxides were based on the $^1HNMR$ and IR spectroscopy and regioselectivity of deuterium exchange reaction. With PTSA as acid catalyst both the cis and trans sulfoxide, 14 and 15 were transformed via sulfenic acid 18 to dihydro-1,4-thiazine 24. However, under the neutral conditions (in DMF at $100^{\circ}C$) the trans sulfoxides 15 rearranged via sulfenic acid 21 to isomeric dihydrothiazines 27. The mechanism of formations of 24 and 27 is also discussed.

• Bulletin of the Korean Chemical Society
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• v.27 no.6
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• pp.835-840
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• 2006

Dimethyl 1-(4-nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate has been used as an ionophore and o-nitrophenyloctyl ether as a plasticizer in order to develop a poly(vinyl chloride)-based membrane electrode for calcium ion detection. The sensors exhibit significantly enhanced response towards calcium(II) ions over the concentration range $8.0{\times}10^{-7}\;1.0{\times}10^{-1}$ M at pH 3.0-11 with a lower detection limit of $5.0 {\times}10^{-7}$ M. The sensors display Nernstian slope of 29.5 ${\pm}$ 0.5 mV per decade for Ca(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. It has a fast response time within 10 s over the entire concentration range and can be used for at least 2 months without any divergence in potentials. The proposed electrode revealed good selectivity and response for $Ca^{2+}$ over a wide variety of other metal ions. The selectivity of the sensor is comparable with those reported for other such electrodes. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Ca(II) solution, with EDTA.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.436-436
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• 1993

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.98-102
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• 1995

The crystal structure of -Ethyl-1,4-dihydro-7-methyl-1,8-naphthyridin-4-one-3-carboxylic acid [Nalicixic Acid] has been determined from single crystal X-ray diffraction study; C12H12N2O3, monoclinic, P21/c, a=8.910(2)Å, b=13.145(3)Å, c=9.370(3)Å, β =100.06(2)°, V=1080.6Å, T=293K, Z=4, CuKα(λ=1.5418Å). The molecular structure was solved by direct method and refined by full-matrix least squares to a final R=0.055 for 1555 unique observed [F0>4σ(F0)] reflections and 166 parameters. The conformation of the molecule is stabilized by an intramolecular O(17)-H(17)…O(14) hydrogen bond [2.525(2)Å, 144.3(10)°].