• Bulletin of the Korean Chemical Society
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• 제7권3호
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• pp.210-213
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• 1986

1,1-Dicyano-2-ethoxycyclobutane (1a) was prepared by [2 + 2] cycloaddition reaction of vinylidene cyanide with ethyl vinyl ether. 1,1-Dicyano-2-phenylcyclobutane (1b) was prepared by the reactions involving the reduction of cinnamyl alcohol, chlorination, cyanomethylation, bromination, and ring-closure reaction. Compound 1a was ring-opening polymerized with NaCN or n-butyllithium to give a low molecular weight polymer. The compound 1b however, failed to polymerize by either anionic or radical catalysts.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1781-1786
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• 2007

Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.579-584
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• 1996

The molecular weight of the purified nucleoside oxidase estimated by gel filtration column chromatography was 480,000 and the enzyme protein was composed of four nonidentical subunits (81,000, 69,000, 32,000 and 16,000). On the basis of the visible absorption spectra and the enzymatic determination of the purified enzyme, the enzyme was supposed as a hemoprotein and also a flavoprotein containing 3 moles of FAD per I mole of enzyme. The isoelectric point of the enzyme was pH 5.1. Addition of metal salts such as 1 mM SnCl$_{2}$ and PbCl$_{2}$ into an enzyme reaction solution inhibited the enzyme activity by 94 and 90%, respectively. The enzyme activity was also lost significantly by hemoenzyme inhibitors such as NaCN and NaN$_{3}$ and flavoenzyme inhibitor, acriflavine and quinacrine. The maximal nucleoside oxidase activity was observed at pH 7.0 and 55$\circ$C. The nucleoside oxidase was relatively stable in the range of pH 5.5-9.0 and below 55$\circ$C.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1664-1670
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• 2003

$NaBH_4$ with catalytic amounts of $MoCl_5$ can readily reduce a variety of carbonyl compounds such as aldehydes, ketones, acyloins, ${\alpha}$-diketones and conjugated enones to their corresponding alcohols in good to excellent yields. Reduction reactions were performed under aprotic condition in $CH_3CN$ at room temperature or reflux. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing system.

• 대한화학회지
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• 제33권4호
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• pp.419-425
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• 1989

1,2,4-Triazine 유도체들을 acetone 용매하에서 methyl iodide와 반응시켜 다양한 1-methyl-1,2,4-triazinium iodide 염을 합성하였다. 또한 이들 염을 10% NaOH 수용액 내에서 $K_3Fe(CN)_6$로 산화시킨 결과 고리 축소화반응이 일어나 1-methyl-1,2,4-triazole 유도체를 주로 얻을 수 있었으나 $C_6$에 치환기가 없을 경우는 미량이긴 하지만 1,6-dihydro-6-oxo-1,2,4-triazine 유도체도 동시에 얻을 수 있었다. 고리 축소화반응은 $OH^-$에 의해 먼저 pseudo base를 형성하고 이 Pseudo base가 1-methyl-1,2,4-triazole과 1,6-dihydro-6-oxo-1,2,4-triazine으로 진행됨을 확인할 수 있었고 또한 1,2,4-triazine의 3개의 질소원자 중 $N_1$ 원자에 quaternization됨을 확인할 수 있었다.

• 대한수의학회지
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• 제40권2호
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• pp.291-299
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• 2000

Magnesium ($Mg^{2+}$) transport across the plasma membrane of cardiac myocytes appears to be under hormonal control. Repeated stimulations with adrenergic or histaminergic agonist produced a progressive decrease in $Mg^{2+}$ efflux from hearts. Thus we hypothesized that the $Mg^{2+}$ efflux may be resulted from a down-regulation of receptors or from a depletion of $Mg^{2+}$ from intracellular pool(s) in the hearts. In the present study, the regulation of $Mg^{2+}$ homeostasis by receptor stimulation was studied in perfused rat and guinea pig hearts. The successive short addition of norepinephrine (NE) to rat and guinea pig, and of histamine (HT) to perfused guinea pig hearts induced a progressive decrease in $Mg^{2+}$ efflux. These $Mg^{2+}$ effluxes were blocked by propranolol or ranitidine, respectively. These decrease in $Mg^{2+}$ efflux were inhibited by sodium cyanide (NaCN), which increases intracellular $Mg^{2+}$ ($[Mg^{2+}]_i$) levels. When NE (or HT) was added after HT (or NE), this efflux was also decreased in the guinea pig hearts. In the rat hearts and myocytes, HT did not stimulate $Mg^{2+}$ efflux. But NE produced a large $Mg^{2+}$ efflux after stimulation with HT. 8-(4-Chlorophenylthio)-adenosine cAMP (cAMP), like NE and HT, also induced a progressive decrease in $Mg^{2+}$ efflux in guinea pig hearts. This effect was inhibited by NaCN. These data provide evidence that the progressive decrease in receptor-stimulated $Mg^{2+}$ efflux is considered to be due to a decrease in $[Mg^{2+}]_i$ levels rather than receptor down-regulation.

• 대한화학회지
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• 제32권2호
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• pp.130-134
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• 1988

수은방울전극에서 바로 시안이온을 시차펄스음극벗김 전압전류 법으로 측정한 결과 검출한계를 낮출수가 있었다. 가장 알맞는 실험조건은 다음과 같다. : 0.1M KCl-0.01M 인산염 지지전해질, pH 7, 석출전위 0.00V, 그리고 석출시간 3분이었다. 이 조건에서 검출한계는 $3{\times}10^{-7}M$ (8ppb) $CN^-$이다.

• The Korean Journal of Physiology and Pharmacology
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• 제3권1호
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• pp.59-68
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• 1999

Chemically induced hypoxia has been shown to induce a depletion of ATP. Since intracellular free $Mg^{2+}\;([Mg^{2+}]_i)$ appears to be tightly regulated following cellular energy depletion, we hypothesized that the increase in $[Mg^{2+}]_i$ would result in $Mg^{2+}$ extrusion following hormonal stimulation. To determine the relation between $Mg^{2+}$ efflux and cellular energy state in a hypoxic rat heart and isolated myocytes, $[Mg^{2+}]_i,$ ATP and $Mg^{2+}$ content were measured by using mag-fura-2, luciferin-luciferase and atomic absorbance spectrophotometry. $Mg^{2+}$ effluxes were stimulated by norepinephrine (NE) or cAMP analogues, respectively. $Mg^{2+}$ effluxes induced by NE or cAMP were more stimulated in the presence of metabolic inhibitors (MI). Chemical hypoxia with NaCN (2 mM) caused a rapid decrease of cellular ATP within 1 min. Measurement of $[Mg^{2+}]_i$ confirmed that ATP depletion was accompanied by an increase in $[Mg^{2+}]_i.$ No change in $Mg^{2+}$ efflux was observed when cells were incubated with MI. In the presence of MI, the cAMP-induced $Mg^{2+}$ effluxes were inhibited by quinidine, imipramine, and removal of extracellular $Na^+.$ In addition, after several min of perfusion with $Na^+-free$ buffer, a large increase in $Mg^{2+}$ efflux occurred when $Na^+-free$ buffer was switched to 120 mM $Na^+$ containing buffer. A similar $Mg^{2+}$ efflux was observed in myocytes. These effluxes were inhibited by quinidine and imipramine. These results indicate that the activation of $Mg^{2+}$ effluxes by hormonal stimulation is directly dependent on intracellular $Mg^{2+}$ contents and that these $Mg^{2+}$ effluxes appear to occur through the $Na^+-dependent\;Na^+/Mg^{2+}$ exchange system during chemical hypoxia.

• 한국동물학회지
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• 제13권1호
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• pp.21-25
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• 1970

초파리의 4가지 계통을 그 발생전 시기를 통하여 NaCl 배지에서 사육하였을때 우화율 SD 작용의 변동을 조사 검토하기 위하여 6가지 농도의 NaCl 사육배지를 만들어 실험한 결과는 아래와 같다. 1. 우화율 SD의 4계통간에는 유의한 차가 없으나 NaCl 농도에 따르는 차이는 매우 유의하다. 2. 우화율은 NaCl 농도가 커질수록 낮아지는 경향이 있으며 0.0M(표준배지)에서 0.3M 농도까지는 NaCl 에 대한 저항성이 강한 편이나 0.5M 이상의 농도에서는 저항성이 급격히 약해진다. 3. 1.0M 이상의 NaCl농도에 대해서는 알이 전혀 부화하지 못하는데 이것은 1.0M 이상의 NaCl 농도에 대한 저항성은 전연 없다고 볼수 있다. 4. SD의 작용 즉 k 값은 SD 계통간이나 NaCl 농도간이나 다 같이 유의한 차를 볼수 없는데 이것은 NaCl배지이더라고 일단 우화만하면 SD작용에는 변동이 없음을 말해 주는 것이다.

• 분석과학
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• 제23권3호
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• pp.240-246
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• 2010

Salicylaldoxime (SA)이 내포되어 있는 미세결정 p-dichlorobenzene 흡착제(p-dichlorobenzene-SA)를 이용하여 시료에 흔적량으로 들어있는 Cu(II)를 예비농축시킨 후 불꽃 원자흡수분광법으로 정량하는 방법을 개발하였다. 시료 용액의 pH, 킬레이트제 salicylaldoxime의 양, 흡착제 p-dichlorobenzene-SA의 양 그리고 시료 용액의 흐름속도 등 여러 실험조건을 최적화하였다. 여러 공존이온에 대한 방해효과를 조사한 결과, $CN^1$가 다른 이온들보다 비교적 심하게 방해하였다. $1\;{\mu}g\;mL^{-1}\;CN^-$에 의한 방해효과는 Ni(II)를$20\;{\mu}g\;mL^{-1}$ 되도록 조절한 결과, 완전히 제거할 수 있었다. 본 방법으로 얻은 직선 감응범위, 상관계수($R^2$) 및 검출한계는 각각 $3.0\sim100\;ng\;mL^{-1}$, 0.9901, 및 $3.1\;ng\;mL^{-1}$ 이었다. 본 방법을 실제 시료에 적용가능 여부를 확인하기 위해 수용액 시료(폐수, 저수지물 및 시냇물)와 식품시료(오렌지 쥬스, 생계란 및 탈지분유)에 응용하였다. 회수율은 93~104% 범위이었으며, ICP-MS를 이용하여 직접 측정한 값과 본 방법으로 측정한 값을 비교한 결과, 95% 신뢰수준에서 잘 일치하였다. 본 방법을 쌀가루 인증표준물질(certified reference material, CRM) 시료에 응용해 보았으며 좋은 결과를 얻었다. 실험 결과들로부터 본 방법은 여러 실제 시료에 들어있는 Cu(II)를 농축 및 정량하는데 응용할 수 있음을 확인하였다.