• YAKHAK HOEJI
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• v.13 no.2_3
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• pp.67-70
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• 1969

Gall duct cannulated rats were given daphnetin, umbelliferone, 4-hydroxy-coumarin, dicoumarol, 4,7-dihydroxycoumarin, 4,7-dimethyl-5-hydroxy-coumarin, coumarin-3-carboxylic acid, cinnamic acid, ferulic acid, caffeic acid by duodenal catheter at room temperature and output of bile flow was detected. All of the subjected compounds in this experiment indicated a significant effect on the biliary elimination except cinnamic acid alone. It is suggested that a relationship exists between chemical pattern and biological activity for coumarin derivatives and their precursors, and that the choleretic activity of these compounds requires hydroxylated cinnamic acid structure as the most fundamental chemical pattern.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1025-1032
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• 2008

(4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester (3a) are efficient and selective coupling agents for the amidation of carboxylic acids. Amidation of aliphatic and aromatic carboxylic acids with aliphatic and aromatic amines using 3a under mild condition gave chemoselectively the corresponding amides in good to excellent yield. Three protected-dipeptides were also synthesized from N-BOC-Phe and O-Me-amino acid hydrochlorides using 3a under mild condition.

• Polymer(Korea)
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• v.26 no.6
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• pp.701-709
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• 2002

To synthesize a new positive photosensitive polyimide precursor, parts of carboxylic acid groups in poly (amic acid) were esterified with 4,5-dimethoxy-2-nitrobenzyl bromide in the presence of K$_2$CO$_3$/HMPA followed by the chemical imidization of residual carboxylic acid units. The chemical structure of resulting polymer was characterized by $^1$H-NMR, UV/vis and FT-IR spectroscopic methods, and its thermal properties were examined by DSC and TGA. Upon UV irradiation, 4,5-dimethoxy-2-nitrobenzyl moiety underwent the photodegradation. As a result, the polymer became soluble in alkaline developer due to the formation of carboxylic acid moiety, which was used to make a micron-sized positive pattern. Sensitivity curves were obtained from the gel fraction experiments with respect to the various 4,5-dimethoxy-2-nitrobenzyl ester contents. From those curves, the sensitivity was ranged iron 4000 to 6000 mJ/㎠, and the contrast was measured to be from 3.1 to 4.9.

• The Journal of Natural Sciences
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• v.7
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• pp.47-51
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• 1995

In order to develope new asymmetric catalyst, we synthesized the following new sulfonamide derivatives start from S-Indoline-2-Carboxylic Acid via the following 5 steps. Hydroxy methyl derivative(1) was thus treated with methane sulfonyl chloride in the presence of triethylamine as base to give mesylated derivative(2) in 85% of isolated yield. The mesylate compound (2) was treated with excess sodium azide to give Azido derivative (4) in 95% isolated yield. Azido compound (3) was then reduced to the corresponding amino derivative in near quntitative yield by the hydrogenation under hydrogen atmospere in the presence of catalytic amount of Pd-C. The amino derivative (4) was converted to its sulfonamide derivatives by the treatment of compound(4) with triisopropyl benzene sulfonyl chloride in the presence of triethyl amine as base. Finally t-BOC group of the compound(5) was removed by the treatement of excess Trifluoro-acetic acid in near quantitative yield to give the target sulfonamide derivative (7) .in this paper we prepared compound(6) in 49% overall yield via the 5 steps of synthesis starting from t-Boc- 2-hydroxy methyl indoline(1) which cab be easily prepared from commercial available S-indoline-2-carboxylic acid by known methods. we plan to apply this new catalyst for the asymmetric reduction , diels-alder reaction, aldolcondensation reaction in due courses.

• Polymer(Korea)
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• v.36 no.4
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• pp.513-518
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• 2012

Polyamide 12 (PA12) oligomers (oPA1) were prepared by dispersion polymerization of ${\omega}$-amino carboxylic acid and dibasic acid in a dispersion medium, thermally stable hydrocarbon liquid paraffin, YK-D130 (a step polymerization). The molecular weight and various properties of other oligomeric PAs (oPA2) obtained by bulk polymerization without the medium were compared with those of oPA1s. The oPA1s showed lighter white color and narrower molecular weight distribution than oPA2s at the same molecular weight. Moreover elastomeric poly(ether-block-amide) (PEBA)s were synthesized with oPA1 and oPA2 as hard segments and poly(tetramethylene glycol) (PTMG) as a soft segment. The molecular weight distribution, and mechanical property of the PEBA originated from the both oligomeric PAs were characterized.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.453-458
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• 2012

Reactions of (N-isocyanimino)triphenylphosphorane with (1R)-(-)-campherchinon in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2604-2608
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• 2013

An efficient synthesis of 2,2'-dipyrryl ketones has been carried out from pyrrole-2-carboxylic acids using trifluoroacetic anhydride (TFAA). Simultaneous generation of both mixed anhydride and 2-unsubstituted pyrrole, via facile decarboxylation with in-situ generated TFA, made their cross reaction (intermolecular Friedel-Crafts acylation) possible and efficient.

• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.119-126
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• 2012

Carboxylic acids play an important role in both aerobic and anaerobic metabolic pathways of both the snail and the parasite. Monitoring the effects of infection by schistosome on Biomphalaria alexandrina carboxylic acids metabolic profiles represents a promising additional source of information about the state of metabolic system. We separated and quantified pyruvic, fumaric, malic, oxalic, and acetic acids using ion-suppression reversed-phase high performance liquid chromatography (HPLC) to detect correlations between these acids in both hemolymph and digestive gland gonad complex (DGG's) samples in a total of 300 B. alexandrina snails (150 infected and 150 controls) at different stages of infection. The results showed that the majority of metabolite pairs did not show significant correlations. However, some high correlations were found between the studied acids within the control group but not in other groups. More striking was the existence of reversed correlations between the same acids at different stages of infection. Some possible explanations of the underlying mechanisms were discussed. Ultimately, however, further data are required for resolving the responsible regulatory events. These findings highlight the potential of metabolomics as a novel approach for fundamental investigations of host-pathogen interactions as well as disease surveillance and control.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.127-127
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• 1993

작약의 메타놀에기스를 작용성분을 추적하면서 분리하였으며 EtOAc 분획으로부터 gallic acid methylester(GA-1) 및 paeonoldmf 혈소판 응집억제 작용 물질로서 분리하였으며 Paeonol은 혈소판 응집억제 작용이 이비 보고된바 있다. GA-1은 오가피로부터 혈소판 응집억제 작용물질로서 분리된 DBA-1과 구조적으로 매우 유사하며 혈소판 응집억제 작용물질로서 알려진 aspirin의 구조와 유사하다. Platelet aggregometer을 이용하여 DBA 및 GA analogs 13종(DBA-1-10 및 GA-1-3)들이 ADP 또는 collagen에 의하여 유도된 혈소판 응집에 대하여 억제작용을 보이는가를 검색하였다. 이들중 aspirin과 유사하게 억제작용을 보인 DBA-1-3-7-9-10, GA-3 및 paeonol에 대하여 mouse를 이용한 in vivotlfgja을 시행하였다. 즉 endotoxin 또는 collagen 과 epinephrine을 정맥주사하여 intravascular thrombosis를 일으켜 혈소판수를 감소시키며 이때 이들 물질들의 혈소판 감소 억제효과를 관찰하였다. 대조약물로서 사용한 aspirin은 collagen과 epinephrine에 의한 혈소판 감소를 현저히 억제한 반면 endotoxin에 의한 혈소판 감소에는 효과가 없었다. DBA-9, -10, GA-3 및 paeonol은 endotoxin에 의한 혈소판감소에 대하여 약한 억제효과를 보였으며, 검색시료 전부가 collagen과 epinephrine에 의한 혈소판 감소에는 aspirin보다 작용이 적었으나, DBA-10, GA-3 및 paeonol은 현저하게 억제효과 있었다. 또한 collagen과 epinephrine 동시 투여에 의한 치사 실험에서는 DBAD-7, GA-3 및 paeonol이 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 인체유해 중금속이온인 Hg(II), Cd(II)등이 NaCl같은 염화물이 함유된 시료용액에 공해이온으로 존재할 경우 흡착에 의한 제거가

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1262-1266
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• 2010

In this study, we investigated the use of liquid crystals to selectively detect the activity of enzymes at interfaces decorated with oligopeptide-based membranes. We prepared a mixed monolayer of tetra(ethylene glycol)-terminated lipids and carboxylic acid-terminated lipids at the aqueous-liquid crystal (LC) interface. The 17 amino-acid oligopeptide SNFKTIYDEANQFATYK was then immobilized onto this mixed monolayer through N-hydroxysuccinimide-activation of the carboxylic acid groups. We examined the orientational behavior of nematic 4-cyano-4'-pentylbiphenyl (5CB) after conjugation of the 17 amino-acid oligopeptide with the mixed monolayer assembled at the interface. Immobilization of the oligopeptide caused orientational transitions in 5CB, with a change from homeotropic (perpendicular) to tilted alignment, which was primarily due to the reorganization of the monolayer. The orientation of the 5CB molecules returned to its homeotropic state after contacting the interface containing ${\alpha}$-chymotrypsin, which can cleave the immobilized oligopeptide. Control experiments confirmed that the enzymatic activity of ${\alpha}$-chymotrypsin triggered the ordering transitions in the LC. These results suggest that the LC can provide a facile method for selective detection of enzymatic activity.